Gear Noise

mick29

Member
Jun 8, 2009
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Salisbury East
Hi Guys, Mick29 here, can anyone help with loud gear noise, ive had about 4 50cc motors some make lots of gear noise and others are quiet, ive just bought a 80cc motors very quiet just sitting running with the clutch in but when in riding it the whining from the clutch gear and crank shaft gear is so loud, is there some good quality gears out there or is there some trick to quieten it down ive glued cardboard to the side cover and put a piece of rubber on the gear cover to stop the noise abit but still noisey, apart from that its a great motor, Thanks Mick29
 

Greg58

Well-Known Member
May 1, 2011
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One of my engines had pretty bad gear whine, I just kept plenty of grease on the gears and rode it. After a few hundred miles it got a lot better, now I don't think its any louder than the other two.
 

maniac57

Old, Fat, and still faster than you
Oct 8, 2011
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memphis Tn
I've seen a lot of small drive gears mounted crooked or machined off center. Might try replacing it if it's real bad. Remove the cover and walk the bike too see how straight the gear is.
Cheap to replace if bad.
 

2door

Moderator
Staff member
Sep 15, 2008
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Littleton, Colorado
I've seen a lot of small drive gears mounted crooked or machined off center. Might try replacing it if it's real bad. Remove the cover and walk the bike too see how straight the gear is.
Cheap to replace if bad.
Ditto: This is very true and usually results in a pulsating gear noise instead of a steady whine. Here's a photo of a primary gear that was machined with less that prefect attention to quality. This puppy was noisy!

Tom
 

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Greg58

Well-Known Member
May 1, 2011
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Newnan,Georgia U.S.A.
Good point, I had assumed he had checked the gears for run out or wobble. Some gears are just so rough cut that it takes a few miles to smooth the edges.