Odd valve shim

I got into the valve with the insulated wire method. Worked wonders when I realized what was going on with the valve and saw that it was visible from the sparkplug threads when opened.

My readings have come back as:

EX--------------------------------IN--------------------new replacements
.178/Y260__________________.152/Y280 --both appear in spec
.127/Y255__________________.063/2,825 --250 Ex *275 or 280* IN?
.102/Y250__________________.076/2,75 ---240 Ex 270 IN
.152/Y245__________________.076/Y275---240 Ex 270 IN

The metric shim numbers threw me off a bit, especially the inbetweener that isn't listed on the chart. I would like to hear an opinion on which of those replacements would be better. I'd assume the 280 if clearances diminish over time. Otherwise could I go ahead and order shims? Is chacal the man to contact? OEM vs aftermarket? Could I use the shims from my parts bike on the off chance they are what I need? Thanks!

 

I wanted to add I'm in Minneapolis. Anywhere locally I can acquire the shims I need? Also the head gasket?

 

Most people on here re-use old shims. (There is at least one person on here who prefers only to use new ones.) Shim pools will always be for used shims. I'd take them from the parts bike if they are the right size.

 

You need a valve cover gasket. Not a head gasket to do the valves. On my 81 I use black RTV instead of a gasket. It only works on the none YICS engine.

Yes you can use shims from a parts bike. But make sure you have a shim in the bucket before you turn the cam.

 

Thanks for the advice on the gasket material. I'll open up my parts bike tonight and hopefully the needed shims will magically be in there. Any idea on that odd inbetween measurement? I would assume the larger clearance would be better. As far as making sure that there are shims installed when turning the cranks, you mean I should take my old out of spec shims and swap them one at a time so that there is always a shim in place?

 

Measure it with a caliper. Then you know what it it. And I would go to the looser side.

 

If you use the chart here: http://www.xjbikes.com/Forums/viewtopic ... valve.html

There is only one shim size that puts it in spec. With a .063 clearance and a 285 shim you need to go to a 280.

You might have noticed the bucket has a lip on it. I'm not sure you'd hurt your cam rotating it over top of a shimless bucket but I don't want to find out.