83 XVZ12 engine issues.. help?

[stevestloo]

First I would like to say that I have been reading the forums a bit, trying to figure out my problem..

 

See, my bike (83 XVZ12) was sitting in the shed for almost 2 years. I figured it would be a good time to clean the carbs (something I am not comfortable doing myself.) The man at the shop was very kind and insisted I try to Seafoam it first. So I added almost 16 oz to about 1.5 gallons of gas, ran it for a bit on idle (to clean out the idle circuit) and let it sit for about 2 days, then ran it again. Ran through the entire Seafoam/Gas mixture, added regular gas to the tank, and to me, it runs a little better.

 

One problem It has is that it idle's funny. I start the bike cold with the choke on until it's idleing at 3000 or so RPM, then slide the choke off. If I slide the choke all the way off, it will stall every time. Not sure if that is a feature or a bug, but I adjust the choke to get it to about 1000 RPM idleing. It idle's reasonably smoothly now.

 

Until I try to give it throttle..

 

When I give it slight throttle, the first thing it wants to do is stall. Often times it does. Giving it very little throttle will drop the RPM to about 5 or 600 before it kicks up.. 1000-2000RPM is sloppy, after that it sounds like a mean machine and the gas seems to work pretty good.

 

I think it's a carb sync issue.. what do you all think? I spent the morning trying to make one of those "home made DIY carb sync" tools with 3/16"ID tubing and connectors, and when I hooked it up, the fluid rushed towards the carbs almost too fast for me to shut the bike off in time.

 

Do you think I just need to get the carbs sync'd?

 

Thanks,

Steve

[Rocket]

Try seafoam again, but at various throttle positions, to clean out the other jets & passageways. Best done under load, as in riding it. Some say to ride it like you stole it, to give it a good workout. This may take a few tanks to clean it out, before changing the plugs & syncing the carbs.

 

Hopefully you will not need to tear into the carbs, for a more thorough cleaning.

 

[stevestloo]

Thank you!

 

I just put another 2 gallons or so in the tank. I will add a can of Seafoam, then fill it up, ride it around, repeat maybe once or twice.. then change the plugs and get 'er synced : )

 

Thanks for the advice! Any advice that contains "ride around" is the best.

 

Now to get it insured and registered..

[bkuhr]

Sounds like diaphrams are not keeping up with throttle plates as you open throttle. Read posts on inspecting diaphrams and temp repair with liquid rubber if you find holes, and replace with new when you can.

Could also be vacum leak in numerious places, and 83 venture YICS is known to leak. spray starting fluid(lightly) in area of carb boots, YICS chamber, YICS hoses and see if engine speed increases. If so you found a vacum leak. YICS can be completey removed from MC, but need hefty vacum plugs to replace the YICS hoses at the heads:080402gudl_prv:

[skydoc_17]

Hey Steve,

If you could take a moment and fill in the part of your profile where it tells everyone what state you live in, perhaps one of the members in your area would be happy to stop by and help you with your VR! Usually when these bikes have been sitting for a while the Carbs. get gummed up. A few cans of Seafoam and a few nice long rides is the best medicine to clean them out. This will not cure worn out parts, or modify adjustments that need to be made but this time of the year, with the weather sooo good, any ride time is good ride time. Good luck with your project, almost ALL of the First Genners have been where you are at one time or another.

Earl

[GeorgeS]

Also, completly drain the fuel tank after you get it run down close to empty. Simply remove the hose from petcock to drain. flush the tank another time.

 

Then, open the Drain on Each Carb bowl, and let the fuel pump run, and pump fuel thru each carb bowl drain for a few min. each one seperatly. You want to make sure fuel is freely flowing thru each carb.

 

Also its advisable to replace the fuel filter--

 

With engine hot, remove the Air Filter cover, and filter, watch the Carb pistons " Danceing back and forth, to see if all for seem to be functioning. If not, they you might have a problem with the Diaphrams.

 

As above-- take the bike out and ride it hard !!! for a few tanks, then a new set of plugs, and a Carb Sync, would be called for.

 

Also, lubricate all of the carb mechanical linkage

 

Also, check the Clamps above, and below the carbs, Intake leaks are a big problem on these bikes. Also, check the 2 bolts on each intake manifold, right at the cylinder head. These are allen head bolts, and not easy to get a wrench on all of them.

[Squeeze]

The Choke Behaviour you see somewhat normal.

 

 

Now, get some Sea Foam in the Fuel again and ride it like you stole it. One of the major Points is, Sea Foam (or any other Product) can't work it's Wonder in only some Hours. Some Passages, like the Pilot Fuel Area your currently fighting with, are very very tiny and the Sea Foam needs to have a Lot of Time to work. Get a strong Mixture it in the Tank, ride half the Fuel out of it and leave the Rest sitting over Night, Gas up the next Day and ride it like you stole, working your Way throughout the RpM Range with Load on it. Let the Motor pull up to Redline every other Time in second or third Gear. In the Afternoon, put some Sea Foam in the Tank, forming a stronger or not so strong Mixture depending on what you felt over the Day and let it sit over Night again.

 

This might go on for over a Week until all the Fuel Passages are free. If the poor Idle Behaviour isn't History by then, you most likely will have to take the Carbs out and clean them on the Bench or, even better in an Ultrasonic Cleaner.

[stevestloo]

Thanks for the help everyone..

I am going to run some Seafoam through it over the next few tanks of gas. 1 Can to 1 tank to start, adjusting as necessary (though if that doesn't clean it out after a few tanks, then, well, screw it )