I have an '04 that has been stalling at idle.  I bought her with ~4600 miles, and probably should've checked the valves right away (who knows if the PO did it at 4kmi?)  Well, the stalling got worse, to the point where I had to choke her at lights just to keep running and get home from my last ride.

Here's what we've done:
-Plugs look good
-air filter isnt too dirty
-took the carbs off, air bleeds look clean, waiting on some gaskets before I take the float bowls off.  Maybe both idler jets are clogged?
-figured we should do a valve check, found the LH exhaust valve is smaller than the smallest feeler.  (.034mm)

All others are in the ~.075mm range.. Is it normal for one to wear so quickly?  I guess I just measure this shim and order the next size down, as the shim still seems to rotate when I turn it.  Could this be the cause of my stalling?

I need to make a shim removal tool... Any hints on how to do that?  I see the picture in the haynes manual..

Thanks all,

Ed

The bucket depressor tool is $15...might be worth it if you plan to keep the bike for a while (or other Suzuki bikes).

Do you know what other suzi bikes take the same shims? 

For example, maybe if I asked for GSXR shims the local dealer would have them. They dont seem very helpful either way though. 

I think it might be faster to make a tool than to buy one.  Or maybe use the zip tie method to get the tight one out for measuring... This way I could order the tool and new shim at the same  time. 

The season is melting away, between parking lot jerks and waiting for parts to ship...

Quote from: viggen on July 27, 2010, 10:51:02 AM

.......................................I need to make a shim removal tool... Any hints on how to do that?  I see the picture in the haynes manual..

http://img.photobucket.com/albums/v443/jcp8832/ValveShimTools.jpg

The 29.5mm shims are specific to various GS500 models. GSX-R shims will not fit without a shim under bucket retrofit.

Also, the exhaust valves loose clearance very quickly. It's generally recommended that you run a wider gap on the exhaust than the factory recommends - .08 - .13mm would be a good starting place. Wear should fall off significantly.

Thanks guys!  I got the shim out with some screwdrivers, a magnet, and some wrestling, being careful not to nick the camshaft in the process.  It turns out to be a 2.75mm shim, and it wouldn't rotate with the camshaft in the 'measuring position.'  Based on the idea that I want to run a loose exhaust valve, and since it's pretty tight, I'm going to order a 2.65mm shim and hope for the best.

This has turned out to be a great and very active forum so far.  Hopefully I'll be cruising along pretty soon.

I'm also going to drain the carbs to get any water/rust out while I'm in there.

Would a valve this tight be the reason my bike won't stay idling without the choke on?

my left cylinder exhaust valve has no clearance either. all others are within spec.

im hoping my tight one is as fat as yours as ive got a load of spare shims but they are all 2.65 or less.

ill find out tomorrow when i attempt to pull the tight one.

i dont know enough to be certain but i wouldnt think this would cause you issues at idle. maybe a combination of this and carbs unbalanced or some other carb issue.

T1, hope it all works out for your valve adjustment.  I found a link to Z1 enterprises on this forum and they sent me shims in about 2 days (RI to NY).  Good thing I ordered so many.  Still couldnt fit the smallest feeler (0.038mm) with the 2.65, but the bucket would just barely spin.  When I put the 2.60 in, I still couldn't fit the feeler in?? I think that I should have rotated the engine a couple extra times to work out the oil and assembly lube, because simple math tells me that should have worked. 

I put the 2.55 in and now my 0.102 mm feeler fits in there, just barely.  Next size is 0.127mm and won't fit.  Given that the valve was soooo tight, maybe this was causing the revs to hang when I adjusted the idle? 

Between this and the freshly cleaned jets, I'm hoping the thing runs like a top now.  I didn't get the gas tank on last night cause it was getting late, but everything else is assembled.

Suggestions for a 'test tank?' 

Thanks all for the help!

Quote from: viggen on August 05, 2010, 06:41:02 AM
... Given that the valve was soooo tight, maybe this was causing the revs to hang when I adjusted the idle? 

Yes, a tight exhaust valve will cause a floating idle, and if you blip the throttle, rpms returns slowly to idle.

Decided to do a compression test before putting everything back together.  130 on the right cylinder, 105 on the left.  Left is the side with the tight valve.  Sloshed some oil down the spark plug hole on the left cylinder and compression went through the roof...  like 150, bouncing up to 170 when we shut it down. 

Do I need rings?  I'm thinking maybe...   Or is the lower compression because I set the valve too tight...  and I added too much oil to the cylinder?

This is so frustrating..  Still gonna try to run it once the oil drains out of the cylinder 

your compression figures seem ok to me.

i dropped a 2.55mm shim in and now can get up to 0.10mm guage in there so im gonna leave at that.

Nice work T1.  That's just what I did, 'cept it took a bigger change to get there.

Hope she runs great for you.

I'm starting a new thread on the compression, cause the LH cylinder actually went DOWN when it heated up.  Weird.