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Post by scooterpimp on Feb 1, 2015 11:46:57 GMT -5
Donuts & correct timing go together. !
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Post by humanshield on Feb 1, 2015 18:31:48 GMT -5
Oh...checked the compression again today with engine warmed up and about 1/2 hour total run time on it.
152 psi
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nightriderrv
Scoot Enthusiast
Never Give Up- Ride all the time !!!!!
Posts: 177
Location: Western mountains Nebo NC
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Post by nightriderrv on Feb 1, 2015 18:35:39 GMT -5
Yep donuts to the rescue again !!!!!
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Post by humanshield on Feb 1, 2015 19:03:50 GMT -5
Now that I can get it started pretty much every time I want to get it to run good. Right now it will barely move. So tomorrow I'll get my trusty vintage strobe timing light out and check the timing. I assume if it's on the mark, the "T" on the flywheel will be right at the pointer mark on the case. I imagine the CDI adjusts the timing on these things a bit at different rpm's ?
Don't worry, it's donuts and coffee BEFORE and during.
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Post by Corrosion on Feb 1, 2015 19:19:15 GMT -5
Oh...checked the compression again today with engine warmed up and about 1/2 hour total run time on it. 152 psi Thanks, a 30% increase. Must have been valve timing. The lash wouldn't have changed. What's your guess.
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Post by katastroff on Feb 1, 2015 21:30:26 GMT -5
Oh...checked the compression again today with engine warmed up and about 1/2 hour total run time on it. 152 psi Thanks, a 30% increase. Must have been valve timing. The lash wouldn't have changed. What's your guess. The slack in the chain, its caused your timing to be out.
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Post by humanshield on Feb 1, 2015 21:40:14 GMT -5
Thanks, a 30% increase. Must have been valve timing. The lash wouldn't have changed. What's your guess. The slack in the chain, its caused your timing to be out. Katastroff, I would absolutely agree with you except for one thing.....when I could not get it started the timing chain tensioner was fully extended making the timing chain too tight. I actually loosened the timing chain and that's when it started working. I think that told me that at least on my scooter with a QMB139, having the tensioner too tight can be as bad as having it too loose? Your thoughts?
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Post by Corrosion on Feb 1, 2015 21:53:16 GMT -5
Theoretically you could not increase the valve timing. As it is set by the gears being timed, and the link length of the chain. That should not of changed because the tensioner is on the slack side of the chain. only thing that would have changed would be the frictional effects.
So the Mystery is still a Mystery!
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Post by humanshield on Feb 1, 2015 23:20:27 GMT -5
Theoretically you could not increase the valve timing. As it is set by the gears being timed, and the link length of the chain. That should not of changed because the tensioner is on the slack side of the chain. only thing that would have changed would be the frictional effects. So the Mystery is still a Mystery! Maybe not? The engine was in fact harder to turn before I loosened the tensioner. The obvious would be that that was in fact the problem. I resisted believing that the friction from that could completely stop the little engine from starting, bucking, belching or backfiring at all.... But again, all I did was loosen the tensioner and it's been starting right up ever since. I hope this helps someone else. Thanks corrosion and all you scooter gurus. I have a lot to learn about Chinese scooter engines.
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nightriderrv
Scoot Enthusiast
Never Give Up- Ride all the time !!!!!
Posts: 177
Location: Western mountains Nebo NC
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Post by nightriderrv on Feb 2, 2015 13:56:11 GMT -5
Did you run the tensioner all the way up on the 50cc there is a catch that has to be pushed to release the plunger then when the spring is put back in the top and screwed in place the correct tension is then applied, 150cc has a screw that needs to be turned to back off the plunger enough to tighten the tensioner body down then release the screw to apply the tension.
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Post by humanshield on Feb 2, 2015 17:12:50 GMT -5
Did you run the tensioner all the way up on the 50cc there is a catch that has to be pushed to release the plunger then when the spring is put back in the top and screwed in place the correct tension is then applied, 150cc has a screw that needs to be turned to back off the plunger enough to tighten the tensioner body down then release the screw to apply the tension. Yes sir. I did that after not doing it the first time
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nightriderrv
Scoot Enthusiast
Never Give Up- Ride all the time !!!!!
Posts: 177
Location: Western mountains Nebo NC
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Post by nightriderrv on Feb 2, 2015 18:47:11 GMT -5
Good deal
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nightriderrv
Scoot Enthusiast
Never Give Up- Ride all the time !!!!!
Posts: 177
Location: Western mountains Nebo NC
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Post by nightriderrv on Feb 2, 2015 18:49:31 GMT -5
I would get all the CVT parts unhooked from the engine and pull the plug then take a good listen while it is spun by hand if all is good then look at the CVT closer.
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Post by humanshield on Feb 2, 2015 18:51:44 GMT -5
<abbr>Roger that.
I'm a bit suspicious of the clutch. Already put a new variator and belt on it. </abbr>
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