Valve Clearance Pain

[professore]

I had my second go at doing the valve clearances on my Revere 650 today.

I dismantled half the bike and removed the valve covers, following the haynes manual religiously setting TDC etc and noticed that the bolt that you tighten with the locknut did not seem to have any clearance at all, however it was worn on one side, and on that side there was clearance

Everything went well, I used a 0.15 mm feeler gauge for the inlet valves and an 0.20 mm for the exhaust. Put the whole thing back together and started her up. It sounded like 2 leprachauns had somehow gotten into the cylinders with a small hammer and started belting away for all their worth.

I then waited a few hours, took off the rear cover and tried again (ok probably a bad idea as engine not completely cool) checked them again, had a friend verify I wasn't crazy while doing it, but the leprachaun must have hidden himself well as he was off again when I put it all back together.

Spoke to an ex-bike mechanic and he said it sounded like all the clearances were too loose. I really can't understand this ... I checked with a gauge one up from the one I used etc and it didn't fit ... It seems that if I go down 0.05 mm with each gauge it will give me a better result, but then I'll be too tight according to the manual. Any ideas ?

By the way bike sounded fine before I started

[Jake]

Sept 18, 2010 14:02:03 GMT -5 professore said:

It seems that if I go down 0.05 mm with each gauge it will give me a better result, but then I'll be too tight according to the manual. Any ideas ?

By the way bike sounded fine before I started

If it sounded fine before you started, then going down by
0.05 mm is probably your best bet.... In fact the tolerances
are quoted as plus or minus 0.02 mm for each.

[professore]

Hi, I figured out the problem. Setting 'RT' and 'LT' is not enough, there is one wrong and one right one in each 360 rotation of the crank. The way to know is to take out a spark plug and poke a screwdriver in. If the screwdriver can make it past where the bottom of the sparkplug was it's wrong; it should hit the top of the camshaft if it is actually at Top Dead Centre (TDC). Thanks to a mechanic buddy of mine for this tip. By the way this is not in the Haynes manual.

[professore]

Also should add that now I know how to do it, it really isn't difficult - the hardest part is getting the front cylinder off. If you can do that you certainly can do it !!!!! It takes about 2 hours once you have the hang of it.