Time to start the definitive VM Carb thread

[satchmo]

Thanks.........I'll live with it for now. And replace later if I can.

I've got the bodies back together, and am just checking the slides and stuff.

I had a couple of bad o-rings, and all of my floats were out. The factory setting was 26mm and most of them were between 20 and 22mm .......

So that was probably why they were running rich right??

So what's the procedure for a manual sync?


Satch

[KEITH KRAUSE]

Yes, the floats being that much out of adjustment would cause a rich condition. 26mm seems a bit high but if that's what your manual says...
You did'nt mention anything about your air and pilot screws. How did things go with them? Also, did you replace the rubber manifold o-rings? Very important.
A carb sinc' using a vacuum tool is very important to get the carbs truly synched. I have manually synched carbs the best my eyes will allow but still not come close to what the tool does. A good manual sinc' makes the tool sinc' a lot quicker and easier.
If just one carb is pulling more vacuum than the others, that carb will run richer and vice-versa. So I recommend buying a tool such as my Motion Pro ($39). If you can do a carb rebuild, you can tool sinc' your carbs.
Ok, here's how to adjust the fully closed and fully open throttle valve positions, manual sinc'.
Fully closed position first. Turn the idle screwknob out to create a good clearance between its tip and the throttle pulley. Hold the carbs with the ENGINE side of the carbs facing you. On top of the throttle valve arm is a slotted screw held by a nut. Loosen all 4 nuts. Make sure the bolts are tight that connects the throttle pulley to the throttle shaft and the throttle valve arms to the throttle shaft(3 ft/lb). You may or may not have a "master carb", but start the sinc' with that carb if you do. The master carb would be #3 from the left. While watching the bottom of the carb slide, turn the slotted screw to fully close the valve or as much as it will drop down. DO NOT turn it any more than necessary. When the valve stops dropping, you stop turning. Do the other 3 the same way. Now carefully hold the slotted screws so they can't move and tighten the holding nuts. 3 ft/lb is good. Don't over-tighten. If you think the screws moved when you tightened the nuts, re-sinc'. When done, the bottoms of the slides should look uniform to the eye.
Now the fully open position. There is a slotted screw under spring tension mounted on the carbs bracket, the throttle stop screw. When you open the throttle the pulley will stop when it hits this screw. Turn the carbs so the FILTER side is facing you. Raise the valves fully by pushing up the pulley until it hits the screw. Hold that.
Look up inside the rear of the carbs and note the bottom of the valves. The bottom of the valves should be 0.5 to 1 mm above the top of the intake chamber. If an adjustment is needed, turn the screw in to decrease this gap and out to increase the gap. Now turn up the idle screwknob enough for the bike to start and idle. This 0.5 to 1 mm gap is for my GS1000 VM26mm carbs. I am assuming your 22mm carbs would be similar.

[satchmo]

Well the carbs are back together I'll attempt the manual sync tomorrow.

In total, I replaced all 4 needles - 3 indents from the top by the way.

3 air screws and accompanying o-rings. - the last one wouldn't come out.
All the main jets, and pilot jets and seat assemblies.

The o-rings on the main jets and the fuel screws.

I hope these are the manifold o-rings you're talking about Keith.

I reset all the float heights to spec. which was 26mm according to both the suzuki and clymer manuals.

I've reassembled everything. And don't have any parts left over.

Thanks for all the help everyone. Now I guess it's time to buy a carb tool to vaccuum sync them all, and hope it all works.

Satch

[KEITH KRAUSE]

Sounds good.
Two things, turn the side air screws out 1 3/4 turns. This should be in the ballpark. When the bike is warmed up, adjust them for the highest idle. Where were the pilot screws set?
The manifold o-rings are inside a groove in front of the rubber manifolds. The manifolds are between the carbs and the head. They are not expensive and yours are probably getting cracked/brittle unless they have been replaced recently.
This will cause intake leaks. Do yourself a favor and replace them while you have the carbs off. You can't do a sinc' with intake leaks.
When you replace them, give them a good coat of hi-temp' bearing grease and torque them about 6 ft/lbs. You probably still have the phillips screws holding the manifolds. I would replace them with allens so you can torque them. Just don't over-tighten them. This just flattens out the o-rings too much and decreases their service life.

[satchmo]

Will do. Thanks for all your help on this Keith, and everyone else who answered all my questions in doing this carb rebuild.

And to anyone contemplating doing this, if I can, anyone can.

Satch