When I cleaned my carbs. I had to remove the accelerator pump nozzle (Lucky CD Haynes Manual pg104 fig 4.2) I noticed that the wieght was present but the small ball-bearing was not present. I reassembled and have been running the xz with no problems until today.
In slow moving traffic at standstill the engine sounded as if it was misfiring. It was irregular - occuring at 1,500 revs. occaisionally.
This did not happen under acceleration or when revving the engine.
Is this related to the ball bearing or is another problem developing?
Any ideas would be appreciated Thanks.
The accelerator pump nozzles don't operate at idle or in slow moving conditions, so that missing ball shouldn't be causing the rough running. How warm was your bike running? When mine gets hot - sitting in traffic (even with the cooling fan running) - I get real bad stumbles, coughs, etc. That's why they added the fuel circulation system on the 83 carbs. The fuel in the 82 carbs heats up & you get vapor locking.
Happened to me in a loooooooong construction delay yesterday. A couple miles of moving at idle. No time to shut the engine off. That sucked! Had to continually rev the throttle to keep the fuel flowing & the bike running. It even died on me once & was a real b!&@# to get restarted. At least I kept up with traffic by pushing with my feet. ::)
H2O
Why dontcha just put the petcock in Pri when you get to that type of driving condition? Let gravity alone get the fuel to the carbs?
I had my times in conditions that you relate, but my Vision had nary a problem aside from not wanting to turn the engine over after it had been stopped. It would start if you "bump" started, and I rue the day that the OEM's took the kick off of the street bikes...
Thanks for your advice guys.
H20- The bike had been running a while so it shuold have been at optimum temp. and it was hot weatherwise.
ironb12s- I'll try that next time.
How difficult would it be to fir '83 carbs to '82 bike?
Extra hose to the petcock on the '83 Vision. If it's a vent of some sort, you can likely get away without taking it to the petcock, or at worst, replace the petcock?
Quote from: Paul@Sheffield on October 11, 2007, 03:45:08 PM
How difficult would it be to fir '83 carbs to '82 bike?
not as easy as you'd think... you'll also need the 83 airbox and 83 rear engine mount (or mod an 82 mount?) I think Superfly and/or the leftcoast guys would know exactly what's involved....
Paul, I prolly have one of those balls or two kicking around... pm me with addy and if you're patient, I'll get one or two to ya if you need 'em
Can ya ditch the old plenum and go with pods?
83 carbs on an 82 is not "just a carb swap". The second line is a fuel circulation system, not a vent. That requires the 83 petcock. The 83 petcock does not fit the 82 mounting holes on the tank, so you need to modify it or get an 83 tank. The upper rear motor mount for the 83 has a larger opening to clear the carbs. The airbox base is 'notched' for more clearance. The motor mount can be modified to clear.
I'm currently working on the swap. Was reluctant to get into it because of all the ancillary parts required. Managed to find them all, so I decided to go ahead. Should be ready for installation by Spring, 2008. Tank needs de-denting, liner & paint. Carbs need total rebuild (have the kits).
As I understand it, the airbox is necessary on the Vision to stop the stumble. Individual filters have been tried, but without much success. It's probably doable, but the problem with these carbs is airflow velocity, not volume. The vacuum flapper door helps create the velocity. If it ws a successful option, I'd love to get rid of the large airbox & reshape the tank to hold more fuel. Another gallon would make it an incredible sport tourer. ;D
H2O
As an aside, GMANINDUSTRIES make auxiliary tanks for the Suzuki V-twin cruiser line. Add up to 2 gal in the space under seat in front of the swingarm. I'm working with Predator to make a SS 2-1 system for my VS1400, and we may be able to do something with GMAN along the same lines.
If Night Vision doesn't have the balls ;D ;D, i do....
Blake did a lot of testing with a VFR meter trying to get pods on them & came close, doing a lot of jetting changes, but never got them to work.
the fact is, these carbs flow more air cfm's than the engine can handle. the vacuum flapper in the airbox is there to restrict airflow & also induce low pressure over the carb throats.
it's a lot like when everybody used to put 750 double pumper Holleys on 350 chevy engines because they saw all the car magazines using them in build ups. what they didn't bother to note was that those engines also had Edelbrok intakes, Headman headers, crane cams, retarded timming, ported heads, lighter flywheels, etc, etc, etc.
--Lucky
"Would be you'd get most poetical 'bout yer pecker... " (catch it, Aelwulf?) ;D
Aelwulf and I know the reference, just kiddin' Lucky... :D It's a Firefly thing.
Ah, to be young and stupid once again...I recall those days, when I had that '71 Challenger with a 318cid and Rochester 2-bbl carb (which, strange as it might sound, strongly resembled the carbs on a Vision) tuned with vacuum guage, terrorizing unsuspecting Corvettes and the like with that Slap-Stick shifter... But, we're getting off topic again. ;) But it's akin to what the Vision does to those unsuspecting Hardley-Ablesons... LOL And why the carbs were the least of my worries when I first got Viky.
Yammie did what they could to keep meddling hands out of the airflow, din't they? So be it, where there's a will, there's a way, and given time someone will break the lock. We're working on a 1 or 2 to 3 intake with pods for the Yammie triples...no damper door on them beasts to hold us back.
Better stick to the '82 carbs then, unless you're looking for a challenge. :) I'd be happy just to work on mine, and like I posted oin another forum recently: work may suck, but being without sucks more. JMHO, that. ;)
Thanks everybody? As the the problem isn't a big issue (at the moment) I'll stick with the '82 carbs.
The missing ball does not seem to be an issue, from these posts.
I haven't done the throttle valve mod yet. I can't remember where I read it-something about sticking a coin to one side off it.
Dare I say the two most despised words in NASCAR? Restrictor Plates? If its too much airflow for a modded air filter, why not restrict the flow below the carbs? Would that work?
David
Has to have variance is why it isn't a plate that is bolted on, as in NASCAR. I suppose the restrictor in the XZ case COULD be another butterfly in the boots to the head, but space is limited and it would require twice the hardware to pull off... not to mention, 2 more things that need adjusted when tuning the carbs.
I will have to look for that door when I work on Viky again...never noticed it before, and might explain a few things...there is a vacuum hose involved with the movement of said door, no?
Quote from: ironb12s on October 12, 2007, 01:19:37 PM
there is a vacuum hose involved with the movement of said door, no?
only on late 82 & all 83's. early 82's were spring operated (sudden throttle opening creates low pressure, pulling the door open)
Yamaha offered a free factory update that included ft carb top, disk filter for the front carb, upgrade rear p.a. jet, replacement airbox top & filter.
Now you really have me wondering about my XZ. I have NO IDEA what is at work on mine, never dug that deep into, or don't recall what I found. ???
Lil' while back, H20 told you that the pump doesn't work at idle or low speeds, that's not entirely correct. It operates when you twist the throttle from any speed, but only when there is movement of the throttle cable. It sends a spurt of fuel into the throats above the butterfly, to augment fuel delivery to the bores. It takes a little while for the vacuum to pick up in the bores after you open the butterfly, and vacuum/venturi effects are what draw the fuel out of the bowl.
There's a good how-to thread in the Technical section of the top banner. I'll be referencing it when my time comes...
Lucky, don't you mean that sudden throttle opening lowers the vacuum in the intake path? So, it's less 'negative' pressure that causes the door to close, slowing the airflow into the intake path? As the engine picks up speed and vacuum with it, the door is "pulled" open.
The highest vacuum occurs at the moment of the butterfly closing, and the engine is still overdrawing the mixture until it can slow to match the butterfly. Fuel is drawn mainly from the Pilot/Idle circuit when the butterfly is shut.
There is no vacuum controlled slide on the XZ carbs, is why it reminds me of the Rochester 2-bbl that I had.
I know the accel pump operates with the throttle at any speed, but at a constant, low RPM, it shouldn't be causing the problem he describes. Guess I could have been clearer. Was going for brevity.
H2O
Hey, i'm just glad Ironb12s is here to set things straight...
THANK YOU, Lucky, thank you... 8)
Sorry 'bout that PM concerning cables. Tiger's busy with a gaggle of Visionaries, I'll ping him when the time comes...
Yeppers, I been wrenching for nearly 40 years now. I tend to overinvestigate things when I work on them, and come off as a know-it-all sometimes, I'm not. I will dutifully admit, I'm a doer of all, master of none. Smarter than the average bear, as it were.
Looking at the cross section of the carb, the aforementioned ball is none other than the check valve for the Accel Pump? Should be rather easy to replace, just get the size from an expert here, mosey on down to your local bicycle shop and let them you're missing a ball... ;) a very *small* ball, that is. ;D
ironb12
Is the ball vital? I am reluctant to pull the nozzle out of the carb body when the bike is running otherwise o.k.
It is as you probably know a 'delicate' procedure using mole grips.
The ball keeps fuel from being sucked in like a regular jet. I suspect if the ball is missing its pulling extra fuel through the accelerator pump schnozzle.
Thanks. I will replace it next time I have the carbs off.
Do you think I will have to adjust the tickover/ idle speed once fitted?
If you've tuned it with the ball missing theres a good chance the accelerator schnoz was leaking, so yeah i'd re-tune it.
Even if it doesnt do anything, at least you'll fell better :D
Quote from: Paul@Sheffield on October 16, 2007, 10:29:56 AM
ironb12
Is the ball vital? I am reluctant to pull the nozzle out of the carb body when the bike is running otherwise o.k.
It is as you probably know a 'delicate' procedure using mole grips.
If it is the BALL for the accelerator check valve, yeppers, it's impotent. (nyuk, nyuk, nyuk) ;)
http://www.ridersofvision.net/Technical/Carbs/carb3.gif (http://www.ridersofvision.net/Technical/Carbs/carb3.gif)
You could post a pic of the place where it's missing from. As there is only one pump, the fuel is piped to both nozzles from it. Would cause a rich running condition if fuel was being drawn thru the open valve in the pump. However, if you are anywhere else BUT the pump, it's not the BALL we are referring to...the pump is a bolt on accessory to only one of the carbs; the pump well has been dummied off in the second.
ironb12s,
From your link it is definately the ball below the accelerator pump nozzle.
I checked the spark plugs and looked to be the correct colour (light grey) i.e. not running rich (black sooty.)
However I don't want to be wasting fuel.
Unfortunately, the ROV Techie on the carbs is only for the 1983, but they weren't THAT different from the 1982. If the ball is missing, then I would look to replace it. The diag shows that it should be there, so I'd make sure it was, and in the right location related to the weight. That ball can be found at any bicycle shop, easily. And, I repeat, that pump is only on one of the carbs...
Unfortunately, my only reference is from a rather foggy memory of taking mine apart back in the 'day'. That reference model is currently 1800 miles out of reach... If I had one to look at, I'd be better able to advise. So's how's 'bouts our local contingent of techies weigh in? At least you have some closer reference than I do. Tiger, Lucky, H20?
Not to be a smart a** ,but if the ball wasen't vital they wouldn't have put it in there in the first place. If you take your air box top off and stuff a rag in the carb throats you can reinstall it with a minimum of hassel . I probably have one, if you want it PM me and'll send it to you no charge.
Quote from: Rick G on October 18, 2007, 01:38:08 AM
Not to be a smart a** ,but if the ball wasn't vital they wouldn't have put it in there in the first place. If you take your air box top off and stuff a rag in the carb throats you can reinstall it with a minimum of hassel . I probably have one, if you want it PM me and'll send it to you no charge.
Better a smart arse, than a dumb arse. ;)
I had better fit one then. I'll try and get one here, if not I'll pm you (Rick G).
Thanks.
Oaky-dokey, has any of'n you Visionaries ever measurated the check ball to see what size BB it is? I'm just guessing, it's around a 5/32", or a 2mm.
nope, I haven't bothered measuring it because at least three of us with balls have offered to send him one or two