QuestionI have a honda 1971 sl 125 ko engine that I have been working on. However when I went to time the engine I lined the mark on the casing with the circle on the sprocket when I place the piston at T mark. I have my valve spacings at .002 each and my points at.014. There is no wobble in the cam shaft when I put it in.I have good compression valves are seating. When I do line up that circle like I said earlier it doesn’t exactly line up perfect when I have it on the T mark it is like a half a jump off. My chain is adjusted to a good tension. Also, my lines on my points plates dont line up either. I have it running but when I rev it up it starts to sputter and just recently when I was playing with it. I could let it idle and it would start to rev up by itself a little and white smoke like oil is getting into it. Whats that about and how would I adjust things so that everything lines up right.
AnswerStephen, If the cam timing marks are not lining up correctly, either the camchain is stretched way out or the crankshaft sprocket is incorrectly aligned on the end of the crankshaft. It isn't uncommon for things to be a little off after years of service, but if it is half tooth off, then those are the only options to correct.
You must set up the ignition timing so that the points open on the F mark alignment. Check the spark advancer mechanism to be sure that it is moving back and forth, smoothly.
White/gray smoke from the exhaust is oil burning, probably from rings not seated in yet, unless it is worn out. Did you check the ring gap clearances in the cylinder bore, as well as piston clearances?
Engines don't just rev up from idle for no reason:
Either the fuel level is dropping from a restricted fuel flow or gas cap vent hole blockage or the spark advancer springs are weak and allowing the spark timing to advance, which speeds up the engine. Check for vacuum leaks at the carburetor and insulator spacers.
Bill Silver
