Valve Shims and clearances

OK I have a 1983 XJ750 maxim.

I had a oil leak from the valve cover gasket so am replacing the gasket, while I am at it am checking the valve shims and are replacing if neccesary. Talked to lenny goin to order the YICS tool and doin a carb job next, but first I wanted to see if I have read this right. From what the hayes manual says the valve clearances are

Inlet .11 to .15 mm
Exhaust .16 to .20 mm

At this time I have Inlet #1= .12, #2=.16, #3=.14, #4=.14
Exhaust #1=.21, #2=.16, #3=.19, #4=.14

So If I read this right I need to dismantle the bike and determine the shim, for #2 inlet decrease by .05, for #1 exhaust decrease by .05 and increase #4 by .05. Now I measered these with METRIC feeler guages and I guess what I am asking is if they only increase/decrease the shim by .05 is the .01 that I am off worth the time and trouble to do the extra work.

 

Yes, your analysis and size changes needed are correct.

Yes, you want to pull out the currently-installed shims on the ones that need replacing and replace with the properly sized shims, espcially on that #4 exhaust. Tight exhuast valves are a disaster waiting to happen. And besides, any further tuning that you wish to do on the bike (synch, color-tuning) is basically a waste of effort and time if your valve clearances are not set properly!

 

+1. Too tight is too tight, even by .01mm. Reason being, they tighten as they wear; if it's "just too tight" now it will be "really too tight" real soon and how often do you want to do this, anyway?

 

Not sure about your use of the words "increase" and "decrease".

For example, on the #2 intake, which is a bit too loose, you want a .05 THICKER shim in order to fill in the gap, reducing it to .11. Conversely, for the #4 exhaust, you want a .05 thinner shim in order to increase the gap.