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1971 CT 70H it has not run well in 35 years--I removed the points and replaced with a CDI. After install I had trouble getting good grounding points, but was able to get a spark with additional ground wire from frame to engine.
I had it running at idle, but it stalled out when I gave it throttle. It idled quite well (not at the moment however)...after the first engine run, when warm, I heard tapping/slapping and figured it was a loose cam chain or the valves were not set correctly. I checked and reset the valves and just looked at the cam chain...now I have a spark problem that I didn't have previously.
The problem is the spark is happening at the very end of the kickstarter travel. Almost 150-180deg before a spark happens. Prior to this, I tore the engine down completely, separated cases and it's back together. I know my cam chain sprocket "0" mark should align with TDC mark--it doesn't. I can't seem to marry the two up. I thought I was on the compression stroke when I set this valves this last time. Anyone with a CDI, can you let me know if your TDC mark and cam sprocket align as they once did with points?
 

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As long as the "O" on the cam sprocket is a 1/2 tooth before the notch in the head (due to counterclockwise rotation) you should be fine with that setting; the valves are still closed. You just need to verify that the piston is at TDC in the cylinder when the "O" is aligned with the notch.
 

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Discussion Starter #3
Thanks for the reply...I’ll verify tomorrow, but I think my cam sprocket “o” is at a 3 o’clock position while at TDC.
 

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One more complete rotation of the flywheel by hand will bring the cam sprocket around by a 1/2 of a rotation, putting it close to the notch and the piston should be at TDC again.
 

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Would that be the compression stroke—That’s when I should check valve lash? Perhaps I set the valves on the exhaust stroke. May have accounted for my late spark when rotating the Kickstarter. I’ll check.
 

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The piston will be at the top of the cylinder EVERY time the flywheel is at the T.

But the cam, and cam sprocket, only turn 180° when the flywheel turns 360°.

The compression stroke only depends on the position of the cam. So set your timing...cam timing, and points timing, only when BOTH the O, and T, marks line up.

Hope that all makes sense.
 

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Discussion Starter #7
Yes, that all helps! I took both the stator cover off and cam sprocket cover and fed the chain around the cam sprocket until the flywheel woodruff key was in line with the "o" at 9 oclock. I kept the cam in the right spot and rotated the flywheel to the correct position by freeing up the chain as it turned. Not sure if that's the correct way, but after an afternoon of working on it--it's running again on first kick! Also, had a clearance problem with my CDI wire guard where it enters the stator cover coming in contact with the flywheel. Thanks all for the help. Some carb adjustments and I should be OK.
 
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