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Post by dandanman232 on Jul 24, 2020 9:52:21 GMT -5
Hey I just put a bbk on a guys scooter for him and when I start it as soon as it fires there is a screeching sound like from the timing chain or the starter gear in the cvt not sure. Has anyone had this problem and if so what is it and how can I fix it
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Post by pinkscoot on Jul 24, 2020 10:30:47 GMT -5
It could be anything. What model scooter are we talking about?
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Post by dandanman232 on Jul 24, 2020 10:56:27 GMT -5
2019 kymco super8 I really think it’s the timing chain something is too tight or out of line idk it cranks and runs but that second before it starts it screeches and it has me scared bc it’s not mine and my 150 does the same thing and I never figured it out so I drive my zuma
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Post by tortoise2 on Jul 24, 2020 11:37:00 GMT -5
Potentially related link? |
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Post by dandanman232 on Jul 24, 2020 11:56:50 GMT -5
Link? It’s not a product
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Post by GrumpyUnk on Jul 25, 2020 7:30:55 GMT -5
If all that was done was a BBK, then there are a couple things that come to mind. The timing chain and the starter Bendix.
If the Bendix gets stuck in the OUT position, it will be engaged when the crankshaft is moving on its own. That means the starter armature is turning at supersonic(exact term.) speeds. I lied. The Bendix will be turning a multiple of the rpms the crankshaft is rotating at. It is NOT designed to rotate that fast, so will complain.
Second would be the timing chain. You could remove the cam/valve cover, and the chain tensioner, and rotate the ctankshaft. Note how well and freely the chain follows the cam sprocket as it rotates. It should be 'square' to the plane of the sprocket, with no curves... You should be able to feel at least a slight amount of slack in the chain. I would rotate the crankshaft using the blower wheel, perhaps with the spark plug removed, and note how nicely the chain moved over the sprocket. If it seems OK, put back together.
One last thing would be an oil control ring that got mangled on installation. They can be jammed in place if you find someone ham-handed enough to force the piston in place with a ring hanging out of position.
tom
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Post by dandanman232 on Jul 25, 2020 8:24:57 GMT -5
I fixed it all I needed to do was put a shim on the starter gear in the cvt. I ended up burning the starter up trying to fix everything but it’s all good now and I have to say this is the strongest 86cc gy6 I have built
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