I just finished a valve clearance check yesterday, and came in to find this interesting post.
I have always used .004" (
inches) on my LIKE200i....and I never worry if I hear a little tappet clicking at idle. A little click just tells me my valves are properly adjusted. For 12,000 miles.(on scoots or in VW's) Actually, if I'm ticking at idle I don't even hear/notice it any longer.
So, I'll add this to the discussion.
This is from an experienced aircooled VW mechanic:"Incorrectly adjusted valves can cause the engine to stall. Too tight, and they don't seal/seat down properly, and will eventually burn that valve. Much too loose and the valve timing changes, so the engine sounds rattly and runs rough. You hear a significant "Clicking" at idle.
If the valve clearance is tight they don't fully close. This just makes for leaking gases. The exhaust gas is the problem here. If it leaks past the valve continuously on each stroke, it heats up the valve (which needs to sit down on the cooler seat to shed some of it's built up heat) and so the valve stretches, which causes it to be opened more, which creates a worse leak.....
If you check your valves very regularly, you could try setting them at 0.004" though instead of 0.006". VW eventually only went to 0.006" so there was more leeway for the valves stretching with age, expecting drivers to be lazy with maintenance. I've always used 0.004", and don't have a tappet noise problem. Mine rarely need adjusting at the regular & frequent check-ups when using 0.004"."Stig writes:
As a longtime VW owner - I was always told that a little valve tappet 'clicking' was the sound of a healthy/happy motor....and I kept my valve lash at .004 with frequent maintenance.
If you take a
.06mm feeler blade in your hands - you will note that it is little more than a piece of metal foil....WAY too small of a valve lash gap for my personal comfort!! And the Kymco sticker states that a variance of .02mm from that .06mm is OK, too.
If you think an .06mm blade is thin - feel a .04mm blade!!!
Made me wonder if the factory sticker maker has mixed up his millimeters and inches ?I check for spare fuses, tight fasteners, when opening the battery cover for the valve inspection.
While I have panels out - I give them a wash.
That's an .004" blade in there yesterday. (FYI- valve lash has not needed changed since November 2014 according to my service records. I check @ every 1200 miles;oil changes at 600 mile intervals)
Again, IMHO - if your valves are adjusted at .004" or .005" - then a little valve tapping at idle is a healthy sound. Worry about something else - because your valves are properly adjusted. I am never going to go to .04mm>.08mm. ....too close to no gap at all for my comfort.
Stig
PS: I use SHELL Nitro 93 octane.