Valve Shim Question

Hi all

Well, the trike was running great, mainly thanks to the help and advice from you guys on here, the Mrs and me went to the European Trike meet in Belgium in July, got wet on the way but no problems 850 mile round trip in 4 days.

Now here is my problem, 2 of the valve seals had started leaking so stripped the cylinder head replaced all the valve seals and lapped the valves in while I had the chance ( a couple needed it). Now I'm resetting the valve shims, so to my problem......my engine is a XJ650RJ (US import) but the cylinder head was changed 18 months ago for a XJ650 (Unknown origin!) My haynes manual has .11-.15mm gap for Intake and .16-.20mm for the exhaust for all models except XJ650 (UK) which, acording to Haynes, is .16 - .20mm for both intake and exhaust.

So, which one do I set the intake to? Or is it a case of try one way, doesn't run right and try the other way and am I likely to damage the intake valves doing this?

Cheers
Lea

 

I'd set them up loose, since they will tighten over time, if anything. Might have a bit of top end noise, but I could live with that.

 

Where they are is the factor. Your skill in wrenching the determining factor.

There's nothing wrong with adjusting them to the TIGHT LIMIT if you have the competence to check the Clearance and make the appropriate adjustment in the future.

The bike's not going to RUN Better either way. Closed is closed.\
But, the Valve Train noise is a bit louder at the LOOSE Limit.

 

Thanks guys, the question was really just to put my mind at ease.

Cheers
Lea

 

Runing the valve clearances at the wider end of the Spec range gives more low end grunt while running them at the tighter end of the spec range give better top end (rpm) performance. Yes it's a real effect..and a standard tuning techinque.
Mid range is obviously the safest, given that these are basically lo performance engines. For me though it's always a struggle to get that 'problem' shim size (there is Always one)