Won't start after adjusting valves

[nslav]

A few weeks ago I checked the valve clearances on my GS while trying to chase down a persistent hanging idle problem, and found that both intakes and the passenger side exhaust were tight.  I ordered one size smaller for each of these and put them in the next week.  After this all clearances were in spec.  I put the bike back together and tried to start it, but it would not start and eventually backfired.  I figured I should order the right tools and recheck the clearances (I was using a set of imperial feeler gauges, but ordered a metric set that goes down to .02mm).  The new gauge set arrived today, and the recheck showed that both intakes and the passenger side exhaust are all at .04mm, and the driver side exhaust is at .08mm.  However, I noticed two things while I was doing this:  First, there were little bits of metal around the driver side intake shim-- they were in the notch in the shim seat.  Second, turning the engine over with the plugs out was smooth and fairly effortless until the driver side intake opened.  It seemed to stick pretty hard, which is interesting as I had previously noticed that carb coughing back fuel mixture at low RPMs while syncing the carbs.

The question I was hoping you guys could answer is what should my next step be.  Thanks in advance!

[gregvhen]

Im not sure if the GS has this, never looked into it, but alot of small engines, (yes motorcycles are included in 'small' have whats called a compression release mechanism for easy starting.  theres many didfferant types but what it is is a little trip that will open the exhause port before the actuall cam opens it.  This lets the startor or hand pull start turn the crank easier.  Once the engine gets going the mechanism (usualy by centrifugal force) will no longer open the exhaust.  Maybe you were taking it apart or reasembling, you messed up this mechanism. {again i dont know if the gs has one, i just know they are common on small engines)

Also it could be that your valve springs are not at the right, uhh, springyness. too hard or more likely too weak. depends how old they are, how often the bike is riden, how hard, etc etc.

[Paulcet]

No compression release on GS500s.  The left side intake bucket may be sticking.  Were you able to rotate the bucket when you were replacing shims?

[nslav]

Yes I was able to rotate it, but it did not move quite as freely as the others.