Some '83 questions...

Started by munkyfistfight, March 30, 2015, 11:43:26 PM

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munkyfistfight

Last summer I acquired a really nice '83 in the Pittsburgh area. The bike runs just fine but needed a jump to start because the battery is dead. When I bought the bike I was given a laundry list of the stuff the guy had done to it, but after working on these bikes for the last 10 years I know what he didn't do to it. So now that the weather has warmed up I'm going to get under the hood (so to speak). I've only ever worked on '82's (I've had three of them over the years), but an '83 is all Greek to me. My question is: Are any, if at all, any of the parts interchangable? i.e carbs, wiring, etc. I have plenty of '82 parts. I know some of the wiring harness has been chopped up, but I have 2 spares for my '82's. Also, what goes into working on these carbs? I have a spare set of '83's I got in a trade but they seem a bit more complicated.

He installed a fan switch, so I'm not sure that the wiring is copacetic.

Funny story: He asked $1,000USD for the bike, I offered $750. Two days later I get an email saying something to the effect of "No one wants this bike. Give me $500 and it's yours". Sold.
Those who play by the book will always be beaten by those who write their own. -Travis Pastrana

Re-Vision

Quote from: munkyfistfight on March 30, 2015, 11:43:26 PM
Last summer I acquired a really nice '83 in the Pittsburgh area. The bike runs just fine but needed a jump to start because the battery is dead. When I bought the bike I was given a laundry list of the stuff the guy had done to it, but after working on these bikes for the last 10 years I know what he didn't do to it. So now that the weather has warmed up I'm going to get under the hood (so to speak). I've only ever worked on '82's (I've had three of them over the years), but an '83 is all Greek to me. My question is: Are any, if at all, any of the parts interchangable? i.e carbs, wiring, etc. I have plenty of '82 parts. I know some of the wiring harness has been chopped up, but I have 2 spares for my '82's. Also, what goes into working on these carbs? I have a spare set of '83's I got in a trade but they seem a bit more complicated.

He installed a fan switch, so I'm not sure that the wiring is copacetic.

Most of your 82 parts are best left for the 82's. 83 carbs will likely give less problems and should have an 83 gas tank wherever you use them..

If you want the 83 gas gauge to work you will need an 83 harness.

Most 82 parts will interchange with the 83 model.

Front brakes and struts, rear shock absorber, and carbs from the 83 are considered upgrades for the 82.

Fan switch is a minor concern and probably best left as is.         BDC

turbosteve84

'83 fuel tanks are different from the '82 model? In what way? This is the first time I've heard of this. --Steve
Steve
saddlebums.tumblr.com

Re-Vision

The petcock recirculates the fuel and they have a sensor for the fuel gauge.     BDC

QBS

And, '82 tanks can't mount an '83 petcock or visa versa without a custom fabricated adapter. 

turbosteve84

So on the '83 fuel is returned to the fuel tank like on a fuel-injected bike?
Steve
saddlebums.tumblr.com

munkyfistfight

I have a spare set of '83 carbs. The ones on the bike work but these ones are kind of gummy. I can't get the floats off (and at this point I'm too afraid to try). The plugs are all still there. Should I even mess with those? What's the procedure for working/syncing on those?

Also, a couple of the jets are stuck and the tips have been broken off. Does anyone have a good method for extracting them?
Those who play by the book will always be beaten by those who write their own. -Travis Pastrana

QBS

#7
TS84, yes.  An '82 tank can serve '83 carbs if the carb fuel return line blocked off.  An '83 tank can serve '82 carbs if the fuel return spigot on the '83 petcock is blocked.  Imho '82 and '83 carbs are equally difficult to work on. 

Rikugun

#8
Quote from: turbosteve84 on April 01, 2015, 09:32:11 AM
So on the '83 fuel is returned to the fuel tank like on a fuel-injected bike?
The '82 fuel pump uses a regulator and bypass arrangement to recirculate fuel back to it's inlet side when demand is satisfied via the float and inlet valves.

Admittedly I'm not an '83 owner but my understanding is when demand is satisfied on the '83, excess fuel transfers back to the petcock via the lower fuel line fitting in the picture.

QuoteAn '82 tank can serve '83 carbs if the carb fuel return line blocked off.
wouldn't it require a "T" installed in the '82's fuel delivery line instead to create a bypass route? Again, I'm not terribly familiar with the '83 circuit but thought I remember someone posting about it before. If I'm wrong someone will correct me.
It is far better to grasp the universe as it really is then to persist in delusion, however satisfying or reassuring.  Carl Sagan

Ken Williams

The 83 fuel pump returns excess fuel to the petcock.  The petcock releases this fuel at the top of the tank via a tube protruding from the top of the petcock.  This top release maintains positive fuel pressure at the carbs irrespective of tank fuel level.  If one attempts to use an 82 tank on 83 carbs by plugging the fuel return line, the carbs will receive whatever fuel pressure the pump produces without the effects of pressure regulation.  I don't have direct knowledge of the results of operating in this configuration.  In my opinion it is likely the higher pressure could overpower the carb floats and flood the engine. 

To make the 83 carbs work as designed with an 82 tank, the top of tank fuel return must be implemented. 

Otherwise, I recommend the return line be connected to the supply line.  Since this defeats the fuel pump you could also bypass or remove it.  This method renders fuel in the bottom portion of the tank unusable. 

turbosteve84

OK, how would this work -- '82 carbs using: '83 airbox, the front of an '83 carb (needed for the vacuum line to the '83 airbox), an '82 fuel tank and '82 petcock? In other words, the fuel pump is an '82 with the rest of the carbs being upgraded to '83.

Whew! This Vision thing is complicated!  --Steve
Steve
saddlebums.tumblr.com

Ken Williams

For the 83 fuel pump to function as designed, excess fuel must be returned to the top of the tank as it is with the 83 petcock.  If an 82 fuel pump is utilized, the fuel return line is unnecessary.  This is irrespective of carb vintage. 

Re-Vision

Quote from: turbosteve84 on April 02, 2015, 10:10:39 AM
OK, how would this work -- '82 carbs using: '83 airbox, the front of an '83 carb (needed for the vacuum line to the '83 airbox), an '82 fuel tank and '82 petcock? In other words, the fuel pump is an '82 with the rest of the carbs being upgraded to '83.

Whew! This Vision thing is complicated!  --Steve

Even more complicated, the front of the 82 carb was modified to provide a vacuum for the actuator. The 83 carb top doesn't fit the 82 carbs.      BDC

Rikugun

I guess munkyfistfight's thread has been officially hijacked....

Steve, what are you trying to accomplish with the various parts? Do you not have a complete setup for either '82 or '83?
It is far better to grasp the universe as it really is then to persist in delusion, however satisfying or reassuring.  Carl Sagan

turbosteve84

Glad you asked.

I have an '82. I bought an '83 front carb top and '83 air box. The fuel tank I'm having fabricated is being designed to accept an '82 petcock. Now I'm wondering if I need an '83 fuel pump and petcock to work with this setup.  --Steve
Steve
saddlebums.tumblr.com

fret not

You will find that '83 petcock and or parts are rather rare, and spendy if you can find them.
Retired, on the downhill slide. . . . . . . . still feels like going uphill!

Re-Vision

83 front carb top wont fit an 82 carb.     BDC

Rikugun

Quote from: turbosteve84 on April 02, 2015, 08:32:32 PM
I have an '82. I bought an '83 front carb top and '83 air box. The fuel tank I'm having fabricated is being designed to accept an '82 petcock. Now I'm wondering if I need an '83 fuel pump and petcock to work with this setup.  --Steve
You haven't said but I assume from your response the '82 carb and airbox are not flapper equipped. If that's the case I'd seek out the 82 carb top (or carbs) and flapper airbox for the '82 setup and petcock.
It is far better to grasp the universe as it really is then to persist in delusion, however satisfying or reassuring.  Carl Sagan

turbosteve84

Yes, I have an '82 Vision, with '82 carbs. Converted the carbs to '83 style. Didn't know the fuel pump was different.

So, '83 front carb top and '83 airbox with flapper.

The fuel pump is an '82.

What problems, if any, would I have with this setup? --Steve
Steve
saddlebums.tumblr.com

The Prophet of Doom

If it fits, then probably a late 82 carb top and flapper.  That gives you a full late 82 setup rather than 83.  No problems with that.

I'd recommend trying 120/120 pilot air jets rather than 135/135 (or 130/135).  Consider also replacing your butterfly seals and backing off your accelerator pump by 5mm.