Valve Shim Help

HerrDeacon wrote:

Just wondering, what affect (if any) would these clearances have on power, etc?

If clearances are a bit too wide, not a big effect. maybe a shade loss in power, probably not noticeable. If they get insufficient clearance, all hell can break loose. hard to start, poor running with lack of power, and the valve seats can get fried.

Thanks guys for your replies. I was out of town for a week with no internet and so I'm just getting back to this. I won't be riding too much before winter so I'm going to wait until then to tackle this.

Ron, I found your write-up on removing the cams, great stuff. I'm going to use this when I start in on it. Thanks for taking the time to document it.

Remember, a noisy valve is a happy valve.

Those measurements were recorded in a cold engine, right?

CoreyClough wrote:

Remember, a noisy valve is a happy valve....

Yep . . . Clickin' ain't stickin'

CoreyClough wrote:

Remember, a noisy valve is a happy valve.

Those measurements were recorded in a cold engine, right?

Yes, the measurments were taken cold.

ron i think this is yours

To check clearances only use feeler gauges in the same increments as shims are available, so you need a .05mm, .10mm, .15mm, and a .20mm for the most part, don’t bother with in-between sizes. Take off your right side points cover and turn the engine over slowly while constantly trying to fit a .10mm feeler between the bucket and cam. If at any point of cam rotation the feeler slides through, move up to .15mm and see if it slides through at any point of rotation. If .10mm did not fit, move down to .05mm. What you want to do is find the largest feeler that will fit anywhere in the rotation of the engine for each valve, but we only care in .05mm increments. Why is this? Because shims only come in .05mm size increments. I try to get my valves all where a .10mm feeler fits and a .15 does not fit. This means my clearance is between .10 and .15mm somewhere. I don’t care where in between. For example lets say a .05mm feeler fit, but a .10mm did not. This would mean you would go down one shim size in that valve and theoretically when you recheck you would be right where you want to be, a .10 fits, .15 does not. If you measure zero clearance go down 2 sizes of shim and recheck.
To take cams out of a KZ650 do only one cam at a time. After removing your center tensioner sprocket and the cam caps, lift up one cam while keeping constant tension on the chain where it goes down into the engine and move the cam out of position to the center of the engine. Make sure you keep all slack between the cams and the chain tight going down into the engine. Now your cam is out of the way and you swap your shims then carefully move the cam back into place making sure of keeping the chain tight down in the engine. Tighten the caps to 5.5 ft/lb or so. Repeat for other cam. Why do we do it one cam at a time using this procedure? No retime is needed! Works great. Don’t over tighten the cam caps, trust me, they will strip before you hit 8 ft/lb, particularly the exhaust ones.