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Vibration rpm limit


Discussion at Motorized Bicycle Engine Kit Forum in the Motorized Bicycle General Discussion forum. Hi Is there anything we can do to reduce engine vibration above certain rpm? Why are other engines smoother than ...
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Old 10-17-2008, 09:14 AM
velardejose's Avatar
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Default Vibration rpm limit

Hi
Is there anything we can do to reduce engine vibration above certain rpm?
Why are other engines smoother than our china girls at high revs?
I am new to two stroke engines, sorry if this is a dumb question
Thanks in advance
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Old 10-17-2008, 09:19 AM
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Default Re: Vibration rpm limit

Not very easily. If you have knowledge of and ability to perform a balance job, it would help.
These engines are crude and pretty much unbalanced.
They are 40's technology.
They are made in China with little quality control.
They are under 200 bucks.
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Old 10-17-2008, 09:21 AM
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Default Re: Vibration rpm limit

I have had a couple that were ALMOST as smooth as a Japanese dirt bike engine....others that would go 40 mph, but vibrated so bad, you could hardly hang on.

Going to a 40T sprocket will help, so will balancing your wheels.

I have gone to mounting all engines with small 1/16" thick sheets of lead between the mounts and the frame (4 pcs. total)...works like magic!
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Old 10-17-2008, 10:16 AM
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Default Re: Vibration rpm limit

two things i have done and i love it is one cut up an old tube and wrap around the frame where you mount the engine to and the other is get a lower tooth count sprocket. lower rpm = less vibration
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Old 10-17-2008, 07:06 PM
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Default Re: Vibration rpm limit

any pics of said mods? I don't quite understand...lead? and a tube?
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Old 10-17-2008, 07:22 PM
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Default Re: Vibration rpm limit

Quote:
Originally Posted by Dominate. View Post
any pics of said mods? I don't quite understand...lead? and a tube?
Lead - the metal that bullets are made from. Chemical symbol Pb.

Tube - rubber from an old inner tube.
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