Bonneville America Forums Forums Technical Forums General Tech shims

ok got my measurements and need some input.

exhaust: .305 .305 .356 .356
intake: .203 .203 .127 .127

shim size: 3.048 3.048 3.302 3.048
3.048 2.921 3.048 3.048

new shim size: 3.078 3.078 3.383 3.383
3.076 2.949 3.00 3.00

so does this sound right?

The math is correct, however there seems to be something amiss as a lot of your readings are already at the far end of the scale and the shims you need are larger then the ones available from Triumph.
The gaps seem awfully extreme and your current shims are already pretty thick.
Is this the first valve check?
How many miles on the bike?

yes it is the first valve check and it is about 3000 over due? the bike is a 2002 with 15000.

dog,
The readings and shims just seem a bit off for such a low mileage machine. You did double and triple check the readings? And your micrometer is accurate as well? Check by measuring a few known good feeler sizes.
You may end up having to get shims from a Kawasaki dealer since some are larger then the 3.2 max size Triumph sells. In fact, according to your measurements, one of your shims is already larger in that regard.

so can i go with bigger shims with out hurting the motor, or should i take motor apart and do a valve job?

As long as you can shim it you should be fine. A valve job should not be needed unless you experience loss of compression or something more drastic, and especially with only 15k miles.

thanks for repling.

i just called yamaha their shims go to 3.2 is the biggest, so any ideas on were i can get 3.383 size?

Having never done a shim valve job,would it be possible to double up thinner shims?

no idea where top get them that big.
You know, thinking more about this, it may be a good idea to pull the head to see wtf is going on in there. Maybe the valves are so gummed up they are not bottoming out enough. Maybe a little lapping compound is in order after all. A whole new valve job is gonna cost some pretty pennies since the valves are about $24 each and you also need the $8 seal for each one as well. I cannot figure why the gap is so big other then maybe it was way too tight from the factory and wore the ends of the valves down.

Maybe possible wear on the end of the valve stem and or cam lobe due to a lesser quality lube? Just thoughts since I don't know what oil you are using. They seem huge for only 15,000 miles from what others have said on this site.

Did you use a metric feeler gauge or a standard one with metric markings?

standard one with metric markings

You need to use a feeler gauge calibrated in metric units. The standards ones convert to metric but are not precise enough to get exact clearances.

http://www.mytoolstore.com/kd/kdfeel01.html has a metric feeler gauge for about $15 including the shipping (which is darn near as expensive as the tool!!)

after going over my figures i looks like i put the three in the wrong place on the old shim size. for the exhaust the old shim should have been 3.02 instead i put down 3.302 i believe this is the way my reading are off.

i also feel my readings are so unbalanced because my bike has been running harder on the right cylinder, my carbs have never been balanced, i have bought 20' feet of tubing and made a balancer hopefully i will have it running by this weekend.

I'd be of the mind to re-check everything, just to be safe...

well put my shims in went and went to check gap could not get feeler gage under ant lobs, so i thought i need to let it run and reseat the buckets and shims. cranked it up and it ran but could not get to stay running no stange sounds just would not stay running. started to take all the old shims and reread them. my readings were 2.50 for all but one shim which was 2.55 don't ask me how i gotmy first set of reading but i think a 12pack of bud had something to do with it.

You can turn the rear wheel to seat the shims. I would not re-read anything until that bike is stone dead cold again.

Considering where you are at, you need to completely re-do ALL measurements.