[JDorff]

I'm adjusting the valves on my bike. I measured and figured the shims I needed. the left valve was at .000 and the right was at .005. I got shims put them in and when I checked it they were even tighter. like tighter to the point that the cam doesn't turn as freely as I did before I adjusted it. And before someone says it, yes the shims were thinner not thicker. What am I missing here?????

[450man574]

You need a Valve Job Now.

If you were at .000, you will be doing a Valve Job Soon. It Might Last 3-4 Hours and you will be Adjusting them again.

[JDorff]

i don't doubt that. but I can't figure out why after putting thinner shims in I have less clearance than I had before???

[JimDirt]

Because you were at 0 , it does not necessarily mean that the next shim size you choose was the correct one from the original shim size , what you have to remember is its zeroed out , so as you adjust the gap , it will be tight UNTIL you finally get the gap , so you can go 2-6 shim sizes from your zero reading before you start to actually get the gap/clearance that you need to start getting close to the correct gap

In other words say your original shim is a 250 , and you had 0 gap , so you go to a 245 and you still have 0 , its because the valve surface has worn so much , so you have to go even smaller just to get any gap at all to make up that wear difference , so you may actually end up with a 220 before you start getting even a 0.002 gap , then you still have to get it to 0.006 so you still need thinner shims , so just because the old shim and the new shim are different by a size or so , does not mean that you went far enough to take up the distance the valve face has actually worn

[JDorff]

I understand that and thanks for the help. I left out some info. My confusion stems from the fact that the gap was originally measured at .005. I replaced that shim with a three thou thinner shim and it now measures .003.

[JimDirt]

Did you clean any oil out from under the shim bucket ?? , or get oil in the recess of the valve where the shim sits ? , that could easily add a few thousandths

Also , when you checked the lash did you torque the cam tower down or just snug it up with each check and change of shims till you got the size you wanted ?? , if you didnt torque it down , then when you do your final assembly , if it wasnt torqued when checking , it can change the gap slightly when you finally do torque it because you just lessened the clearance between the cam and the bucket from just snugging it

[riddler9]

Did you clean any oil out from under the shim bucket ?? , or get oil in the recess of the valve where the shim sits ? , that could easily add a few thousandths

Also , when you checked the lash did you torque the cam tower down or just snug it up with each check and change of shims till you got the size you wanted ?? , if you didnt torque it down , then when you do your final assembly , if it wasnt torqued when checking , it can change the gap slightly when you finally do torque it because you just lessened the clearance between the cam and the bucket from just snugging it

What he said. Also be sure to turn the engine over 3-5 times after everything is bolted back up, before you check the clearance.