I just recently bought a 92 and the idle hovers high.  Also, when adjusting with the idle screw in between the carbs, i can make full turns without it affecting the idle.  Just to have the experience, I'm going to rebuild/rejet the carbs.  My questions are as follows: where should I set the idle adjustment to when re-installing the carbs (how many turns in or out?)? Is it possible to turn the idle adjustment too far in either direction?  If I set up both carbs the same way, will I still need to sync them?

This forum has been a great help and i look forward to anyone's assistance with these questions.

=]

I wouldn't say i'm an expert but I can tell you my personal experience with a similar problem. I bought my bike and it was idling high and I thought it was a problem with my carbs and i adjusted them and nothing ever happened. I tried syncing them and couldn't get them the same. Eventually I found that I had only 24 psi in one cylinder! I had a cracked exhaust valve. So you could check the compression. Hope that helps.

thanks! i'll try that as well. i have 2 gs500's  so i was going to swap the carbs over from my runner and see if that helps the idle on the fixer. i didnt even THINK of doing the compression test first.. i was gonna do the valve clearance too but compression test has now definitely been added to the list of work.

Thanks again! i'll be sure to let you know how it goes!

another question few questions: i'll be doing a leakdown test, can the valve cover be off when doing it?  also, what is the optimal psi i should be hitting in each cylinder?

Optimal is above 140psi in both, neither less than 114psi, variance less than 10psi between the two.

I'll double check my numbers when I get home, cause I think I'm off a bit here.

As far as the idle, when I put it back on I screw it in just until it touches, and then twist it a little further. I don't usually worry about it considering I know the choke is going to be on the first time I try to start it , and then as I slowly turn the choke down I'll know if I have to adjust it. If the bike doesn't seem to want to start I'll slowly turn it up.

Ok, just checked the Suzuki shop manual:

Standard  142-199 PSI
Limit  114 PSI
Difference 28 PSI

It's out of spec (needs engine overhaul) if:
- compression in one cylinder is less than 114 PSI
- difference between the two is more than 28 PSI
- both cylinders are below 142 PSI even if they're both more than 114 PSI

Low compression could be:
- worn cylinder wall
- worn piston or rings
- piston rings stuck in grooves
- poor valve seating (valves tight)
- defective cylinder head gasket

Quote from: romulux on April 20, 2010, 06:28:44 PM

Low compression could be:
- worn cylinder wall
- worn piston or rings
- piston rings stuck in grooves
- poor valve seating (valves tight)
- defective cylinder head gasket
- evil little green gremlin inside the combustion chamber huffing all the compression

It's always been the little gremlin in my experiences. Get him with bug spray and pull him out with some really long needle nose pliers through the spark plug hole.