Help with valve adjustment

[JTGS850GL]

I'm in the process of trying to adjust my valve clearance and have run into a problem. On my #2 exhaust I can't rotate the bucket to get the shim out. the shim has close to 0 clearance but the shim will rotate in the bucket. I just can't see the cutout in the bucket and the bucket will not rotate. Any suggestions?

[WilliamGLX81]

Hmmm. I think the bucket spins with the motor, but I'm not sure if they always wind up in the same place (notch inaccessible).
Just to ask the obvious question which way is the lobe pointing?

The ziptie method worked great for me, and even the tight <.03mm valves opened WAY up with the ziptie holding the valve open. I highly recommend it, though some people don't, just because it's so easy, quick, and simple. Just don't use steel zipties :P

Short of that, you could pull the cam, but then all of your clearances will be off, and that's a lot of work to change a shim.

[Agemax]

if the shim rotates then so will the bucket. have a good look round, you will see the cutout there somewhere. get a long thin screwdriver (or similar) and locate it in the cutout and push it round until it is in the correct position for popping the shim out.

[JTGS850GL]

OK, I used a punch and the tie wrap method and was able to pop the shim out of the bucket. Still can't rotate the bucket to get the cutout facing in the right direction, but at least I can get a new shim in. The cutout is directly under the cam facing the outside so it's pretty much unusable.

ALL the clearances measured near zero on both intake and exhaust. Only two measured .03mm with most of the others measuring at or less then .01mm. I inputted .01 since the spread sheet doesn't seem to like 0.00.

My bet is that it hasn't had a valve adjustment on a LONG time. Compression was good at 130 across the board so I'm hoping that the exhaust valves are still OK. Now here's what the spread sheet looks like:


The #2 and #3 exhaust shims were + sizes so those were measured using my calipers. Doesn't look like I can do a lot of moving around of shims except one if I understand this right. The final shim size is what I'm thinking would be right. Any suggestions would be appreciated.

PS, I keep hearing of using a coin to replace a shim when rotating the crank, but nobody ever says which coin. I found that a US .50 coin is close but still too small. So what coin is everyone referring to? Should I pick up a thin (2.45 maybe) shim and use that as a reference shim in the future?

[Nessism]

No need to pick up a reference shim if you keep up with the checks like the manual specifies. The checking shim is for people that never check their valves or just purchased a neglected bike.

As far as the shims are concern, I suggest getting enough of the smaller sizes to move each valve two steps. Get a few 2.50's and 2.45's too, just in case.

[tom203]

If #2 exhaust bucket doesn't rotate when cam lobe pressure is off it, something is amiss-should spin freely.
Aim for high end of clearance to be on safe side- no need to be super precise.

[jsandidge]

spinning bucket

I used a small 90 degree angle pick. It worked great to grab the notch for a little spin. Then I used a small straight pick to pluck the shim up enough to grab it with needle nosed pliers.

[JTGS850GL]

OK, I ordered three 2.50mm shims along with four 2.55 and three 2.65 from Z1. That way I have all shims from 2.50mm to 2.70mm just in case. Looks like I'll have some shims to donate to the shim club. I did check with my local dealer and they said they would exchange shims at $7.50 each and they have a limited selection. What a joke.