getting ready to set the valves on my bike...should i use the haynes manual setting or ?????????????seems i recall there has been some controversy on this thanks stay warm it finally got cold down here in NC today
Some notes: Although the factory figures were .002" and .004" for the 650, west coast distributor, Johnson Motors, recommended running the 650's with .004" and .006". At these figures the valves were not particularly noisy."
"For every problem, there is a solution that is simple, neat, and wrong." H.L.MENCKEN '06 T100 Bonneville '70 TR6 Bitsa, Pazon EI
Boy, this is an interesting bag of worms... I'm not sure some ppl who THINK they know how to set valves DO... probably starting with me. The basic premise behind the idea of setting the valves "slightly loose" is protection. Meaning, if the valves are too tight, they will not be able to cool sufficiently, and they can indeed "burn up". Too loose and performance suffers, and the valves can also be very noisy, as Florida points out. I have tried to set the valves at both clearances referenced above. I think I have been successful, and for ME... and me only, I do notice a difference when the valves are set to factory standards on my 71 T120. But then again, I am careful not only setting them, but checking them multiple times before buttoning everything up. I forgot to point out also, that some riders feel the difference in modern petrol is a good reason to provide a "cushion" that older, lead based fuels provided.
I set mine with feeler gauges to 2 and 4 and it is ok. However, after a very high mileage, the valves can acquire a dent in the top where the rockers bear on them which the feeler doesn't take into account so you get a bigger clearance anyway!
DPO- If you have a unit 650 Triumph the original clearances were .002" inlet and .004" for the exhaust. What you are using, if you haven't written it incorrectly, is 20 thousandths of an inch which is too big. Some people like to set them a little wider than the original book to .004" and .006".
Meaning, if the valves are too tight, they will not be able to cool sufficiently,
The bane of air-cooled engines: how to keep them cooled sufficiently....
The valves need to seat well and uniformly in order for the heat to be dissapated to the head....the head acts as a heat sink for the valves...
If the valve or seat is not Concentric, or the lash is too tight, you end up with hot gases heating the edge of the valve.....then you have a nice glow plug to start the process of preigntion.....it all goes slowly downhill from there.....
'77 T140J "Vintage Bike". What's in your garage?
"The paying customer is always right."
Fitting round pegs into square holes since 1961...
I just realized that DPO was using .020 for both cams because he was using the specs. for degreeing cams as running clearance.As usual DPO was just being consistant. Also I must have a different idea as to what "running sweet" means. I know "a slappy tappet is a happy tappet" but .020 is way past happy! Jack