Riders Of Vision

General => TechTalk => Topic started by: kiwibum on November 12, 2007, 02:02:07 AM

Title: Any 550's out there running with no fuel pump?
Post by: kiwibum on November 12, 2007, 02:02:07 AM
I have a 550 (couple actually) now and about to strip the carbs for a clean before getting it going. I measured the height of the carbs to frame and it is the same on both the 400 & 550. So I'll probably try running with out the fuel pump when I put the carbs back in the 550 since the 400's don't have the pump at all. Is anyone out there happily running with out the fuel pump on their 550 or am I missing some vital information?
Title: Re: Any 550's out there running with no fuel pump?
Post by: Tiger on November 12, 2007, 05:17:15 AM
 :) I think you will find that Brian_Mathewson has run his, without the fuel pump, for several year's without any problem's.

                 
8).......TIGER....... 8)
Title: Re: Any 550's out there running with no fuel pump?
Post by: Brian_Matthewson on November 12, 2007, 08:47:32 AM
Tiger's correct...I've been running without a fuel pump since 2001 with no problems...gravity has worked very well without interruption. You have to make sure you have enough gas to create enough pressure to run through the fuel line at a decent rate. In other words, if your gas only just covers the inlet in the tank, it will not fill the carbs. Put in a gallon & you'll be fine. I'm not sure how much reserve I have so I'm usually conservative about filling up...do it earlier rather than later.
Brian
Title: Re: Any 550's out there running with no fuel pump?
Post by: ironb12s on November 12, 2007, 12:38:44 PM
I don't recall a fuel pump on my 1982.  Butt, it's been a while...
Title: Re: Any 550's out there running with no fuel pump?
Post by: kiwibum on November 12, 2007, 11:50:13 PM
Great thanks, I normally fill up fairly quickly after hitting reserve on the 400 so I'm sure I'll be fine on the 550. I'll try it out and see how it goes. Bit less weight with out the fuel pump too:).
Title: Re: Any 550's out there running with no fuel pump?
Post by: MikeScoot on May 30, 2020, 02:34:26 AM
There are not many recent contributions to this thread. Actually there are not many, recent or not.
So I wonder; are there many of us running without a fuel pump? Seems to me that if it will run without one then there is one less thing to go wrong and, perhaps, less gnashing of teeth.

Cheers,
Mike
Title: Re: Any 550's out there running with no fuel pump?
Post by: The Prophet of Doom on May 30, 2020, 06:00:23 AM
Sure, one less thing to go wrong, but I think you'll find the pump/regulator will help maintain consistent fuel bowl levels. 

If you are worried about shitty old diaphragms, there are quite a few visionaries running electric fuel pumps with good results.  Dry bowls will need a really long wait on PRI without a pump ( my pumpless XZ400 was a total pig to start from empty bowls ), about 20 cranks with stock pump, and nearly instant with electric. 
Title: Re: Any 550's out there running with no fuel pump?
Post by: MikeScoot on May 30, 2020, 07:54:37 AM
Cheers. Thanks for the info.

Just ordered a Polaris diaphram one that was mentioned in another thread.
https://www.ebay.com.au/itm/Fuel-Pump-Polaris-ATV-Sportsman-325-400-500-600-700-Magnum-330-Outlaw-450-525/232078840545?hash=item3608fa12e1:g:NzgAAOSw9NdXrGhW

AU$22 to my door and no need for extra wiring. 

Will report exploits later.

Title: Re: Any 550's out there running with no fuel pump?
Post by: kiwibum on May 31, 2020, 01:21:06 AM
Quote from: MikeScoot on May 30, 2020, 02:34:26 AM
There are not many recent contributions to this thread. Actually there are not many, recent or not.
So I wonder; are there many of us running without a fuel pump? Seems to me that if it will run without one then there is one less thing to go wrong and, perhaps, less gnashing of teeth.

Cheers,
Mike

Hello Mike, interesting to see this post pop up after so long. It was so long ago I had to go check on the bike to remember if I had removed the pump, no pump on the bike. I ran my bike for 3-4 years fuel line direct to the carbs no problems at all. My bikes have been in storage since then, they might see the light of day in 2022 when they become vintage and cheaper to register!

As I mentioned with the 400, as soon as I hit reserve I filled the tank on the 550. Due to the two low points on the tank of the XZ, you are better to keep the tank full on these and top up more regularly than run to empty all the time, this reduces space for condensation and helps prevent issues with water and corrosion in the tank.

Hope that helps and happy riding.
Title: Re: Any 550's out there running with no fuel pump?
Post by: MikeScoot on May 31, 2020, 02:05:41 AM
Yep. That's great information. I will certainly try it with no pump as simpler is better in my book and I want to rule out as many variables as possible.

Ha ha! Two years 'til vintage! Wow! I remember, as I'm sure do most of us, when the XZ was new - last century.

I'll take your advice about keeping the tank full too. There are many whacky design features on this bike and the tank is one of the whackiest. They might have been enjoying some 'odd' matsutake mushrooms that year in the design rooms. Either that or they were fast brewing their own shochu and working with evil hangovers.
Title: Re: Any 550's out there running with no fuel pump?
Post by: kiwibum on May 31, 2020, 03:07:56 AM
Yeah the tank really is a weird design/shape, it has a small capacity for how big it looks on the bike which is just one annoying feature of the bike. I still aim to build a sport cafe racer version out of one of mine, and making a better tank is on the long list of improvements!
Title: Re: Any 550's out there running with no fuel pump?
Post by: MikeScoot on May 31, 2020, 06:21:41 AM
Tricky job with the induction path. Still, they could have accomodated the same size filter in a much smaller airbox volume without too much trouble. There may have been method to their madness but, if so, it's over my head. I suppose you could make it some trick feature of your custom tank and have a big scoop/filter protruding through a tunnel in the tank! Having a tunnel throught it instead of a huge hollow for the airbox would give a LOT more capacity for fuel. Lolol a misfire back through the carbs could be dangerous though! lolol Might wind up eating an air filter! Seriously though, it would make better use of space especially if the tank had a slight hollow on the top to accomodate the filter set up.

Lolol couldn't get much more whacky than it already is.  Of course they got 'round that tank problem with the V-Max by moving it down near the swing arm and then went quirkily bonkers on the fake "tank" by hanging filthy big fake air scoops below it on either side! Ha ha ha. Can't say they didn't have a sense of humour! Spectacular when highly polished!
Title: Re: Any 550's out there running with no fuel pump?
Post by: The Prophet of Doom on May 31, 2020, 06:26:33 AM
Quote from: kiwibum on May 31, 2020, 03:07:56 AM
Yeah the tank really is a weird design/shape, it has a small capacity for how big it looks on the bike which is just one annoying feature of the bike. I still aim to build a sport cafe racer version out of one of mine, and making a better tank is on the long list of improvements!
Hey Steve, long time no see
You still in Rotovegas?  How's it all going?
Title: Re: Any 550's out there running with no fuel pump?
Post by: Rikugun on May 31, 2020, 08:36:50 AM
Just my 2 cents... Is it possible you are looking for problems that don't exist? If your pump can be shown to be defective that's another story in which case disregard the following - although if it were me, I'd fix the pump.

This type of pump is simple and very reliable. They've been used on small engines/power equipment & lawn equipment for years. You'll be able to use all the fuel in the tank with the pump in place. The first time you run out of gas with gas still left in the tank, you may regret your decision. Replacing the OEM pump with an electric pump (IMO) adds a level of complexity not present with one that works on pulses that exist naturally when the engine is running. Although there has been a lot of speculation on the pump's viability, I'm not sure I've read where it was definitively shown to have gone bad. Not that it can't happen, it just seems to be very, very, rare. This is the reason the forum isn't littered with lengthy threads on pump repair and maintenance.

The pumps' viability is most often in question when an owner has a running issue they can't figure out. More often than not, it is eventually traced to one or more non-pump causes. I don't see removing the pump as an improvement but again, just my opinion. If it gives you peace of mind I can't argue those benefits but please know, you are removing one of the components shown to be very reliable.   :D
Title: Re: Any 550's out there running with no fuel pump?
Post by: Walt_M. on May 31, 2020, 01:59:29 PM
As for me, the electric pump is the way to go. Cold starts are so much easier that it reason enough in itself to go electric.
Title: Re: Any 550's out there running with no fuel pump?
Post by: MikeScoot on May 31, 2020, 04:26:28 PM
Quote from: Rikugun on May 31, 2020, 08:36:50 AM


This type of pump is simple and very reliable. They've been used on small engines/power equipment & lawn equipment for years. ...

... The pumps' viability is most often in question when an owner has a running issue they can't figure out. ...

A lot of sense in what you have written. I have a similar pump on the way, but am interested to rule the pump out as a potential cause of running issue and so will try the engine with no pump in order to ascertain whether, or not, it is the cause of my problem (however unlikely that might be). I will have a new replacement pump on hand to use once I have isolated the problem - whatever its cause might be.

Quote from: Walt_M. on May 31, 2020, 01:59:29 PM
As for me, the electric pump is the way to go. Cold starts are so much easier that it reason enough in itself to go electric.

I've heard of this easier cold starting with an electric pump from both you, Walt, and from Rohan in NZ. Thanks for your report.

Cheers to all,
Mike
Title: Re: Any 550's out there running with no fuel pump?
Post by: kiwibum on May 31, 2020, 06:14:29 PM
My bike was running fine when I removed the pump, I just wanted to remove it if wasn't required, they didn't have one on the 400 so why was it on the 550. May be the inlet is slightly higher on the 550 due to the longer stroke and they thought the pump was needed. I agree the pump is very simple and reliable, I see them on mowers with low tanks. I only ran out of gas once on the 550 and there was barely any fuel left in the tank, so for me the pump wasn't required.

I can see how an electric pump might help fill the carbs for cold starts. This could also be achieved with a small manual pressure pump in the gas cap, couple of pumps every now and then to keep positive pressure in the tank pushing fuel out like vintage cars use.

A scoop in the top of a custom tank is an interesting idea, hadn't considered that. I have some of the parts to make the custom bike electronic fuel injection, so the aim is to gain back some space where the airbox was to put more fuel, still another couple of years away before I get to play with it.

Hi Rohan, I'm well, moved to Tauranga couple of years ago, I have a big enough place to have a workshop now so the bikes are on the property with me at least, just need to finish renovations so I have time to play.

Having a quick read through the ROV forums,  I see the same old problems coming up. Good to know there are still the old faces on here sharing their knowledge.:)
Title: Re: Any 550's out there running with no fuel pump?
Post by: MikeScoot on June 01, 2020, 04:29:30 AM
Just been mucking around with some drawings of air filter on top of tank. There are a few problems with the idea. None that couldn't be solved but it would be a big effort to do so. Getting easy access to a fuel cap is one problem, and a means by which to drain incoming rain water without it hitting the filter element is another.

I think the reduction in required space (especially height) if you went to injection might allow the inner 'ceiling' of the tank to be lowered - thereby increasing capacity significantly - and it could all still be hidden away neatly on the underside of the tank.

Cheers,
Mike
Title: Re: Any 550's out there running with no fuel pump?
Post by: Rikugun on June 01, 2020, 06:34:54 AM
Walt, I'm curious about your report of easier cold starts with an electric pump. Do have any theories on why that is? For instance does it over power the inlet valve causing a rich condition? Prophet, do you run an electric pump or are you reporting what other's (Walt?) have found? Either way, same question to you - why easier cold starts?  You guys mentioned cold starts specifically - any noticeable difference when the engine is at operating temperature?

Mike, your "air filter on top" idea is one I haven't heard before. How serious are you about this? Still in a theory stage or have you worked on any prototypes or mock-ups?
Title: Re: Any 550's out there running with no fuel pump?
Post by: Walt_M. on June 01, 2020, 06:45:52 AM
It's simple really, turn the key, tick, tick, tick, float bowls are full. Hit the starter and you're running. The pump does not force fuel past the needle valves. Just make sure to use a pump from a carbureted bike, fuel injection use higher pressure.
Title: Re: Any 550's out there running with no fuel pump?
Post by: Rikugun on June 01, 2020, 06:57:51 AM
I may have interpreted "easier cold starts" too literally. I was assuming any start begins with full carb bowls. So it's just a matter of how you arrive there - turn the key or turn the petcock to "Prime" and wait a bit. I have the same experience without the tick, tick, tick. If it's been run recently the bowls are full. If not run in a while I turn the petcock to prime and wait 30 seconds.
Title: Re: Any 550's out there running with no fuel pump?
Post by: MikeScoot on June 01, 2020, 07:02:02 AM
Quote from: Rikugun on June 01, 2020, 06:34:54 AM
Mike, your "air filter on top" idea is one I haven't heard before. How serious are you about this? Still in a theory stage or have you worked on any prototypes or mock-ups?
Hi Rikugun,
Na, it was just a whacky idea. Could probably work pretty well but the work involved to do it would be more than I can afford.

With regard to the cold starts; I think the reason an electric pump may be better for cold starts is that it would bring the bowl levels to the appropriate height before the motor was even cranked (depending how it was wired). With a mech. pump it would require cranking to pulse the diaphram in the pump before any fuel could be moved. Just a guess.
Title: Re: Any 550's out there running with no fuel pump?
Post by: Rikugun on June 01, 2020, 07:11:15 AM
You don't have to crank a Vision over to fill the bowls. That's what the petcock's "Prime" position is for. There is a slight delay while you wait for the bowls to fill however. I can see Walt's point that it's easier (I now interpret as faster) especially after storage with empty bowls.
Title: Re: Any 550's out there running with no fuel pump?
Post by: MikeScoot on June 01, 2020, 07:28:21 AM
Doesn't the fuel still have to push its way through the pump even when on prime?
Title: Re: Any 550's out there running with no fuel pump?
Post by: jefferson on June 01, 2020, 10:43:46 AM
An experience I had with non ethanol fuel gave me much easier cold starts. Highly recommend not using ethanol fuel if you can find ethanol free. If the bike had been sitting for very long it would take a while to start, but with ethanol free it would crank right up. Put it down to the ethanol fuel evaporating while the good stuff didn't. I also lost 5 mpg going from ethanol free to the ethanol blend.
Title: Re: Any 550's out there running with no fuel pump?
Post by: Walt_M. on June 01, 2020, 12:25:46 PM
Freedom is a wonderful thing. Everyone can do what they want. I am running an electric pump.
Title: Re: Any 550's out there running with no fuel pump?
Post by: fret not on June 01, 2020, 02:11:28 PM
Low pressure pump if you are going to use an electric pump.  I found one with a range of 2  - 4 pounds pressure.

Another thought regarding making a tank is to make the air box before beginning to plan the tank.  In my brother's efforts at the Bonneville slat flats he learned about the importance of air flow into the engine at speed.  The engine needs "calm" smooth (opposite of turbulent) air which is why there is an air box in the first place.  And the air box needs to be at least twice the volume of the engine displacement.  There are complicated programs to actually figure this stuff out if one wanted to dig that deep.
Title: Re: Any 550's out there running with no fuel pump?
Post by: MikeScoot on June 01, 2020, 03:38:56 PM
Quote from: fret not on June 01, 2020, 02:11:28 PM
...the air box needs to be at least twice the volume of the engine displacement.

I agree, but I think a distinction must be made between the volume of the airbox and the volume of air after the filter.  I would suggest that the volume of air between the air filter and the point at which fuel is introduced needs to be as large as possible. The size of the airbox itself - before air is passed through the filter - makes little difference, in my opinion, because it presents no restriction to flow - with the exception of afterthought gadgets like the RK flapper. The air filter restrics air flow resulting in lower than atmospheric pressure between itself and whatever is used to introduce fuel. The greater the volume between the filter and the carbs/injectors the less this reduction in pressure will be, and the lower the fluctuations in pressure, and the lower the turbulence.
The XZ has a huge volume BEFORE the filter element.
Title: Re: Any 550's out there running with no fuel pump?
Post by: Rikugun on June 02, 2020, 06:37:52 AM
Quote from: Walt_M. on June 01, 2020, 12:25:46 PM
Freedom is a wonderful thing. Everyone can do what they want. I am running an electric pump.
Absolutely Walt. And I didn't intend for this to become an electric fuel pump bashing session. Actually, it's a cool mod. I imagine the install is straightforward and they are effective. With my Visions it's been a matter of priorities.  Fuel delivery wasn't an issue so my efforts were applied where needed. I'm not saying I'd never use one - just haven't had to yet.

Quote from: MikeScoot on June 01, 2020, 07:28:21 AM
Doesn't the fuel still have to push its way through the pump even when on prime?

Yes, the fuel passes through the pump on it's way to the carbs. I don't know that it would pass through an electric pump though? Provided you had enough voltage in the battery it wouldn't matter. As Walt said, turn the key and the pump charges the bowls with fuel.
Title: Re: Any 550's out there running with no fuel pump?
Post by: MikeScoot on June 02, 2020, 07:37:51 AM
Quote from: Rikugun on June 02, 2020, 06:37:52 AM
... Yes, the fuel passes through the pump on it's way to the carbs. ...

So even on prime with the motor not running it must pass through the pump - by gravity alone. Not an ideal system - especially since the pump is located some height above the bowls.
I'm warming to the idea of an electric pump, or simply gravity feed without a pump, more and more.

Lol also warming to the idea of getting some sleep as I have to be at work in eight hours from now.

Looking foward to any other ideas on this topic over morning coffee tomorrow.

Mike
Title: Re: Any 550's out there running with no fuel pump?
Post by: Rikugun on June 02, 2020, 08:45:24 AM
I'm scratching my head trying to understand your reasoning here but maybe I need sleep too.  :)
Title: Re: Any 550's out there running with no fuel pump?
Post by: MikeScoot on June 02, 2020, 03:57:27 PM
lolol  I'm just trying to work out why the XZ is somewhat notorious for being difficult to start and frequently runs badly. If we assume, for the time being, that the ignition system is not the problem then we are forced to assume that the cause of difficult starting is the fuel system.

We know that the tank is an odd  design and that the bulk of the fuel is held quite low. This would mean fuel exiting the tank through the petcock would often be under less pressure than that on a more conventional tank.
We know that the bike will run, by available accounts, quite satisfactorily with no fuel pump - but that when the fuel level is low there is not enough pressure through the fuel line.
We have several reports that the fuel system seems to operate very well with an electric pump and these reports claim the electric pump enables better cold starting than the mechanical pump.

So whilst mechanical pumps are, under normal conditions, quite reliable, it seems reasonable to wonder whether the XZ mech. fuel pump set-up is doing a good job of supplying fuel at a satisfactory pressure at all times or not.

lololol I probably wouldn't even be thinking about this if my bike was running well! :-)  But even if it was, we still know the XZ can often be a mongrel to start - and that's a PITA on any engine.

Oh, and another possible factor mentioned in this thread was ethanol fuel.

:-) Off to think about blue sky, flowers, big diesels and narrow winding roads now. :-)

Mike
Title: Re: Any 550's out there running with no fuel pump?
Post by: kiwibum on June 02, 2020, 06:25:53 PM
It is very easy to isolate the fuel pump as causing running problems, put in a direct line from the petcock to the carbs and test with a full tank of gas. I doubt low pressure from low gas level makes enough difference to notice, my bike ran fine when doing run tests with a small plastic bottle of fuel so I could run with out the tank on. One thing that will make a big difference is having a good filter in the fuel line and flushing out the fuel tank properly (same for any old bike).

I don't know if there is ethanol in the gas in Australia but this is another problem to be aware of as someone else mentioned. "Ethanol is hygroscopic, meaning it absorbs water vapor directly from the atmosphere" (https://en.wikipedia.org/wiki/Ethanol_fuel#Post-production_water_issues (https://en.wikipedia.org/wiki/Ethanol_fuel#Post-production_water_issues)). So if you have a ethanol fuel mix and the tank is half empty for the week sitting in a cold garage you can have starting and running problems due to moisture.

Regarding "the XZ can often be a mongrel to start", I think for new owners this is partly learning the best starting technique. The XZ has an accelerator pump like a car so it only needs one twist of the throttle during starting otherwise it floods. For me I found the technique was one flick of the throttle, hold the throttle partly open then hit the starter. Most people are used to twisting the throttle at each kick/push of the button. I also found cleaning up all the electrics connections including earthing wires solved starter motor issues.

What it really comes down to with these bikes (or any old electrical-mechanical system) is taking a methodical approach and isolating each area to remove it from the equation to find the real cause of the problem. My bike ran great once I fixed all the little problems it had.
Title: Re: Any 550's out there running with no fuel pump?
Post by: MikeScoot on June 02, 2020, 10:31:13 PM
Quote from: kiwibum on June 02, 2020, 06:25:53 PM... The XZ has an accelerator pump like a car so it only needs one twist of the throttle during starting otherwise it floods.

Yes, they do flood easily once the system is primed well. I find simply leaving the choke on and leaving the throttle alone works well on most bikes. Once actually fired up a few gentle caresses of the throttle are sometimes needed. Same method worked well on a near new XZ I had back in '84 - also on my VMax.

Also agree that a methodical approach is almost always essential when troubleshooting anything.
Title: Re: Any 550's out there running with no fuel pump?
Post by: Rikugun on June 03, 2020, 09:49:52 AM
I think KIWI makes a great point regarding starting rituals and electrical connections - these cannot be ignored.

Mike, I'm still confused why you think fuel passing through the stock pump to fill the carb bowls is a bad thing? Also, please forgive my OCD. These threads become a record others will use so allow me to question what seem to be a couple of presuppositions? Your comment regarding only fuel system and spark required is true-ish. It's reliable spark at the right time. I'll assume air is included in the "fuel system". Compression was left out of the holy trinity and has to be considered in diagnostics too.

QuoteWe know that the bike will run, by available accounts, quite satisfactorily with no fuel pump - but that when the fuel level is low there is not enough pressure through the fuel line.
Is this what's called a straw-man argument?  :) That's why a pump was provided by the factory. Leave it in and there's no problem. Or, replace it with electric if you prefer.  "...run quite satisfactorily w/no pump..." if you accept limitations not present with the stock setup.

QuoteWe have several reports that the fuel system seems to operate very well with an electric pump and these reports claim the electric pump enables better cold starting than the mechanical pump.
Define "better". All things being equal, 2 bikes with properly filled carb bowls should start equally well. The universe doesn't care if one has a pulse (not mechanical) pump and the other electric. If, both bikes had empty bowls, the electric pump would fill the bowls faster than the OEM setup switched to "Prime". Once full, they start the same.

QuoteSo whilst mechanical (pulse) pumps are, under normal conditions, quite reliable, it seems reasonable to wonder whether the XZ mech. fuel pump set-up is doing a good job of supplying fuel at a satisfactory pressure at all times or not.
You can wonder but you'd have to demonstrate how reasonable it is. I don't see sufficient data to support that claim.  The pump has a regulator and internal by-pass ('83's have a return as well) to supply sufficient flow and pressure to work as designed. And, they've demonstrated over decades to do just that.

No one will judge you for installing an electric fuel pump but don't bash the OEM setup unnecessarily. Visions have enough legitimate issues to bash!  :P Hopefully I haven't interjected personal bias into this but let me know if I have.



Title: Re: Any 550's out there running with no fuel pump?
Post by: Ken Williams on June 03, 2020, 03:50:17 PM
I offer potential evidence that engine starting could be easier with an electric or no fuel pump.  I had ongoing trouble with my 83 that I eventually resolved by replacing diaphragms in the fuel pump.  During troubleshooting I discovered no fuel moved through the pump unless the engine was turning.  Hopefully, fuel will flow through a pump with good diaphragms so the carbs can be filled in a stationary engine with the petcock in prime.  Perhaps someone owning a Vision with the OEM pump will find an opportunity to check. 

Fuel pressure in the 83 is regulated by the height of the return line, located close to the top of the tank.  No internal by-pass is included. 
Title: Re: Any 550's out there running with no fuel pump?
Post by: MikeScoot on June 03, 2020, 03:59:44 PM
@ Rikugun;  I'm not quite sure what it is that you are really trying to demonstrate here, Rikugun.
I'm just interested in making my XZ easier to start and, perhaps, more reliable.
Whether we like it or not, several people here have brought forward information which appears, to me, to indicate the fuel pump may well be a reasonably common cause of, or factor in, starting problems.
Title: Re: Any 550's out there running with no fuel pump?
Post by: Rikugun on June 03, 2020, 07:46:13 PM
@Mike, Seriously not trying to challenge you or be disrespectful, Mike. My apologies. My criterion for evidence is often unrealistically high. Sometimes a few anecdotal accounts are all one has to go by. Moreover, as a wise prophet once said "Tread carefully as information from our USA cousins is not always right for other markets". I neglected to take this into account.

Ken, thanks for the comments. I can't speak to the '83's with any real experience as all mine have all been '82's  I will say all 3 of my 'RJ's filled the carbs with the petcock on "Prime" position.

The factory manual for the 1983 USA RK describes the procedure for removing the regulator cover with 3 screws, then the spring and diaphragm from the pump body. Sounds like the regulator is internal rather than external like the 1982 US RJ's. Do you recall seeing anything like that? It's apparently under the pump diaphragms and valves. Maybe you didn't dig that deep or maybe the manual is in error. It wouldn't be the first mistake found.

Yes, no internal bypass on the RK as it uses a return hose. I didn't make that clear enough in my previous post. Again, no practical experience here but from reading posts on the forum my understanding was the pump return went to the extra fitting on the petcock exclusive to the RK. In the US market anyways. Not so?
Title: Re: Any 550's out there running with no fuel pump?
Post by: kevin g on June 03, 2020, 10:07:26 PM
When I started work on my '83 I rebuilt the carbs and fuel pump and once I found the tiny fuel passage in the idle circuit that was clogged it starts just fine.  It doesn't jump to life like my fuel injected BMWs but it starts right up.

I have proof that fuel will flow just fine through the fuel pump.  I have drained my fuel tank several times by attaching a hose to the overflow spigot and opening the float bowl drain screws.  The tank drains down until the level is at its lowest possible level (where the pump would need to be used).
Title: Re: Any 550's out there running with no fuel pump?
Post by: The Prophet of Doom on June 04, 2020, 04:07:31 AM

If I recall you reported you bike was awesome with a pony tank, and only crapped out when you used the real tank.  That tells me you have a problem that is reducing fuel flow. (For example  blocked/pinched fuel line, blocked pump, perforated diaphragm, blocked petcock, blocked filter screen)  Remember that hundreds, if not thousands of XZs work just fine without requiring an e-pump, so it's more a problem on your bike than an underlying design problem.

Electric fuel pumps are awesome.  Hop on the bike, turn the key and go.  Slightly higher pressure may help overcome reductions elsewhere, so whether it's a problem solver or no you aren't wasting your money.  Fixing underlying causes though will be cheaper and a better first approach.

If it's not correct that you bike is brilliant with a pony tank, then your list of possible causes just exploded.  Sync, mixture, blockages, vacuum leaks and spark are also all good candidates for poor starting and far more common that fuel pump/reg problems.  These units are insanely reliable.

XZ lives matter!
Title: Re: Any 550's out there running with no fuel pump?
Post by: MikeScoot on June 04, 2020, 05:21:24 AM
Hi Rohan,
I appreciate your well intentioned suggestions and comments, and also those of others.
There are, as you correctly state, many factors which can affect starting and running of an XZ engine or any other engine.
I have no reason to firmly believe that the fuel pump is causing me trouble - but nor do I have any reason to rule it out as a potential cause of trouble. But I am happy to have revisited the subject as doing so has revealed more good information.
Cheers,
Mike
Title: Re: Any 550's out there running with no fuel pump?
Post by: Ken Williams on June 04, 2020, 12:12:30 PM
Rikugun, since your 3 Visions all filled their carbs with the petcock on prime, it seems safe to assume that behavior is normal.  Finding a Vision will not fill on prime is apparently an indication the pump diaphragms are stretched, as mine were. 

I also have the factory USA RK manual.  In the RK section, step 3 removes the 6 screws that hold the pump together.  Step 4 removes 3 additional screws to remove the regulator cover etc.  This step was incorrectly copied from the RJ section of the manual.  There are a total of 6 screws on the RK pump.  The RK pump contains diaphragms and check valves, no regulator.  The portion of the RJ pump casting that contains the regulator is not present on the RK.  Also, note there is no discussion of inspecting or installing RK regulator parts or the regulator cover.  After rebuilding my fuel pump, I discarded the unneeded parts from the RJ/RK rebuild kit. 

The pump return connects to the extra fitting on the petcock.  Inside the tank, that line extends upward roughly 8 inches. 
Title: Re: Any 550's out there running with no fuel pump?
Post by: Walt_M. on June 04, 2020, 07:41:53 PM
I did not mention that I have an '82 tank and fuel tap on my '83 so I didn't have to deal with the return line when I installed the electric pump.
Title: Re: Any 550's out there running with no fuel pump?
Post by: Rikugun on June 05, 2020, 06:20:31 AM
Ken, thanks for the clarification. I threw that caveat in about the manual possibly being in error for the very reasons you listed. Seemed odd to not even show a picture of those components. I tried an online parts diagram but it showed '82 carbs and petcock for the '83 model. Not much help there.

QuoteRikugun, since your 3 Visions all filled their carbs with the petcock on prime, it seems safe to assume that behavior is normal.  Finding a Vision will not fill on prime is apparently an indication the pump diaphragms are stretched, as mine were.
I could only go so far to say the '82's likely all functioned like mine. EDIT: I read back through the thread a bit and had missed where kevin g indicated his RK did work as the RJ's. Thanks for the additional info Kevin.

Quote from: Walt_M. on June 04, 2020, 07:41:53 PM
I did not mention that I have an '82 tank and fuel tap on my '83 so I didn't have to deal with the return line when I installed the electric pump.
Sounds like a much easier install that way Walt.
Title: Re: Any 550's out there running with no fuel pump?
Post by: injuhneer on July 03, 2020, 05:49:18 PM
I am late to this party so forgive me if I missed something. I am going to step back a bit. The simple comments here are just for clarity.

A few terms:
Vacuum Fuel Pump - Pump diaphragm operated by vacuum pulsations (stock)
Mechanical Fuel Pump - Pump diaphragm operated connected reciprocating element (cam, lever, etc)
Electric Fuel Pump(s) -
- Diaphram type: electro-mechanical movement of the diaphragm
- Positive displacement (gear, rotor): motor rotates displacement assembly

Now...

Stuff to consider in the quest for delivery:
Head - Amount of standing pressure due to gravity (matters on inlet and if pump against gravity)
Lift - The amount of liquid a pump can lift (suction) in a given system

There are other variables like the fluid itself, the diameter of supply and return (if any), volume per unit time, etc.

In the case of these bikes the vacuum pump only operates with, well, vacuum pulses. This being the reason one side of the diaphragm is connected to one cylinder. The intake pulsations move the diaphragm that in turn moves fuel. The check valves control the inlet and outlet to keep the fuel moving. The small amount of head is needed because the vacuum operated pumps don't pump air effectively if at all. This means that if the engine isn't cranking/running or if you have intake vacuum problems the pump isn't operating. With vacuum pulse present and a pump in good nick it will move fluid.

In the case of the XZ the fuel petcock is also connected to vacuum for similar purposes. Vacuum opens the valve when greater than the spring pressure allowing fuel to flow. PRI bypasses that function allowing fuel to flow by gravity.

I won't go down the mechanical pump road (think old cam/lever automotive fuel pumps) because I don't think anyone is running one of those although a very effective pump could be driven from many points on the engine.

The electric diaphragm pumps are self-regulating by virtue of the pressure relay inside the pump. Residual pressure holds the contacts open. When pressure drops the solenoid cycles and pressure is generated. Most of these require some head to operate. The usually don't have much lift (suction). My personal choice for a pump of this type of implementation is the automatic pump from a Honda CN250 Helix. There is a Virago pump that is nearly identical to the Honda pump. These pumps are durable and will prime and run with just a little inlet pressure (head). Also self regulating and dead reliable. Return line is optional but maybe desirable to circulate fuel.

Electric positive displacement pumps usually have high lift values. These are common on vehicles these days. Many varieties and all with good lift, pressure and output. Probably complete overkill for the bike. No regulation (external regulator needed). Also need a return. They heat the fuel if not allowed to circulate. Also generate enough pressure to overwhelm the float valve in the carb.

That is my little info-mercial.

Go forth and multi-pump!



Title: Re: Any 550's out there running with no fuel pump?
Post by: MikeScoot on July 04, 2020, 07:10:34 PM
Thanks for the excellent summary, Mike.
Title: Re: Any 550's out there running with no fuel pump?
Post by: pinholenz on July 07, 2020, 09:08:58 PM
In my opinion the biggest advantage of not having a fuel pump is that there is one less vacuum tube to leak. Switch activated electric pump makes sense. Presumably the vacuum activated fuel stop diaphragm on the fuel tank tap is also removed. Yet another source of vacuum leakage.

In the last couple of weeks I have been helping mates with flooded engines. They had full tanks and the entire contents of their tanks have ended up inside the engine and the sump. One on a Honda VTX1300  the other on a Yamaha 250 single. The Honda had a vacuum activated fuel stop at the tap, the Yammie was a straight forward fuel valve that had failed. A sticky float valve probably allowed the carbs to flood into the engine in both cases. Very messy, but I haven't heard of the same problem with an XZ.

An ignition activated electric pump that also acted as a fuel stop valve makes a lot of sense. Just carry around a length of pipe to bypass the electric pump if it fails
Title: Re: Any 550's out there running with no fuel pump?
Post by: The Prophet of Doom on July 08, 2020, 03:55:41 AM
Quote from: pinholenz on July 07, 2020, 09:08:58 PM
An ignition activated electric pump that also acted as a fuel stop valve makes a lot of sense. Just carry around a length of pipe to bypass the electric pump if it fails
When I bought my first XZ, everyone told me it was daft to not have a kickstarter, and I'd get stuck somewhere.
Sometimes you just have to trust the engineering - fuel pumps are pretty reliable.
Title: Re: Any 550's out there running with no fuel pump?
Post by: injuhneer on November 06, 2020, 11:06:48 AM
I have an opportunity to a little work on my XZ fuel system.

The 40 year old fuel pump seems to have failed. Maybe diaphragms in the vacuum pump have failed?

Disassembly shows that the main diaphragms are OK. The problem is in the check valve membranes, good old-fashioned wear. The two stage check valves are a thin membrane made of the same material as the diaphragms. The contact surface in the pump has worn these valve membranes. Also of note is that the sealing faces/seats for these check valves appears to have worn also. The the two problems combined result in a failure to seal with each pump cycle.

I will find some suitable replacement material and probably dress/polish the sealing face.

In the meantime I have a Virago fuel pump available. I may just lash this up to see where it can be installed, etc.
Title: Re: Any 550's out there running with no fuel pump?
Post by: The Prophet of Doom on November 06, 2020, 02:28:08 PM

Is it electric or vacuum?  I think you can find Virago models with either.  I've got two electric pumps - both specify that they need to be placed below the float bowls so that  might be something to consider.


Alternatively you can get a diaphragm kit from Keyster for $30 or so on ebay.  Experimentation is always more fun though than just replacing failed parts.
Title: Re: Any 550's out there running with no fuel pump?
Post by: fret not on November 06, 2020, 04:26:58 PM
Electric fuel pumps are available in various pressure ratings.  The one I got is for 2psi - 5psi.  More pressure is not needed or probably wanted.  I figured that as long as the pump makes slightly more than gravity pressure it should be fine because some Visions work well enough with just gravity feed until the tank is nearly empty.  More pressure brings more possible issues like leaks,  and forcing fuel past the float valve.
Title: Re: Any 550's out there running with no fuel pump?
Post by: injuhneer on November 06, 2020, 05:42:13 PM
Quote from: Prophet Of Doom on November 06, 2020, 02:28:08 PM

Alternatively you can get a diaphragm kit from Keyster for $30 or so on ebay.  Experimentation is always more fun though than just replacing failed parts.

No argument there. :-)
Title: Re: Any 550's out there running with no fuel pump?
Post by: injuhneer on November 06, 2020, 05:43:33 PM
Quote from: Prophet Of Doom on November 06, 2020, 02:28:08 PM

Is it electric or vacuum?  I think you can find Virago models with either.  I've got two electric pumps - both specify that they need to be placed below the float bowls so that  might be something to consider.

Electric. It will fit nicely in the V of the engine.
Title: Re: Any 550's out there running with no fuel pump?
Post by: fret not on November 07, 2020, 12:46:01 AM
"it will fit nicely in the V" IF you don't have carburetors.  I have been poking about fitting carbs into that "V of the engine" and I find there is significantly less room for ANYTHING between the cylinders and heads.  Try to remember that parts sometimes need to be removed or adjusted, so access is rather important.  The fewer obstacles you set for yourself the easier Life will be.
Title: Re: Any 550's out there running with no fuel pump?
Post by: injuhneer on November 07, 2020, 11:20:27 PM
Quote from: fret not on November 07, 2020, 12:46:01 AM
"it will fit nicely in the V" IF you don't have carburetors.  I have been poking about fitting carbs into that "V of the engine" and I find there is significantly less room for ANYTHING between the cylinders and heads.  Try to remember that parts sometimes need to be removed or adjusted, so access is rather important.  The fewer obstacles you set for yourself the easier Life will be.

Noted and thanks. With no YICs box in place there is plenty of space. I promise I'll post photos.

I would have mounted it today but instead spent the day making a custom chain tensioner for my son's kart.
Title: Re: Any 550's out there running with no fuel pump?
Post by: Walt_M. on November 08, 2020, 05:48:48 PM
I put mine on the left frame rail and used the FZ fuel filter that came with the pump. In the event of a pump failure, mine doesn't pass fuel if the pump isn't running , I can easily bypass the pump. If there's enough fuel, I can disconnect the pump inlet hose and connect to the filter inlet and go on my way.
Title: Re: Any 550's out there running with no fuel pump?
Post by: injuhneer on October 20, 2021, 10:36:07 AM
Yep, it has been a year. Since I started on the XZ we had a wedding! All of the activity and associated COVID complications consumed my time for many months.

Here is my test rig. This is a Virago pump installed on temporary mounting (right in the V). It works nicely. Click-click-click and the carbs are filled. It did expose a problem. The rear carb float is set a tiny amount too high. Where the factory pump did not deliver enough volume to expose this with the engine running the electric pump did. Now I need to remove the carbs and check/reset the float level(s).

(https://www.ootfab.com/external/Vision/tn_IMAG0075.jpg)