bad bearings

I noticed after i put my motor together that there was alot of engine noise . i put a 70 cc kit on the engine with a new head and carb after i broke the motor in it ran really well. then when i was riding the engine started to perform really while checking that the timing was right i took off the side cover and while looking around i noticed that the pads on the inside of the flywwheel were worn in an unusual manor there are three very distictive lines on each one in the same spot all the way across the area of the pads. so this made me think that things were not staying in wack inside there .so i started to wiggle the fly wheel on the shaft and there seems to be a lot of free play in there. is there supposed to be. any thoughts will be appreciated.


Re: bad bearings

sorry it is a 77 maxi one speed

Re: bad bearings

by "pads" in the flywheel i guess you mean the magnets..

The flywheel should have zero freeplay up, down, in, out or sideways..

Running it with a lot of engine noise may have been a bad idea. You may have bad crankshaft main bearings. However it may only be a loose flywheel. That can cause both poor running (timing is suffering) and noise.

Check see exactly what is loose.. the flywheel or the flywheel shaft itself.

Re: bad bearings

i can clearly see the the shat moving also with the fly wheel .so i am thinking that the bearings were bad.the kid of noise it wass making was kind of mettalic. do you think that that bad bearings could cause the damage that has happened to the magnets.

Re: bad bearings

yes, if the crankshaft bearings are worn, the flywheel magnets may touch the stator (the stator is within the magnets and bolted to the engine block).

Although the clearance between the magnets and the stator is minimal, the bearings must be severely damaged before there can be actual contact.

I dunno what to tell you.. you are sure the crankshaft moves sideways.. bearings are the only thing stopping it from doing so.

Repair involves splitting the engine case open, removing the crankshaft and replacing the bearings and seals and gaskets.. Accuracy when reassembling is critical. Clearances must be observed.. Not too difficult to do and it doesn't require a bunch of tools, but it's not a job for the faint of heart..

You won't be the first person to go into the crankcase and discover that not only are the main bearings shot, the connecting rod big end is also shot, probably due to insufficient lubrication.. Check it out before make any decisions.

Re: bad bearings

Jason Luther /

i think hes refering to me. heh (its quite sad really). its going to cost me double what i payed for the ped to fix it :( -jason

Re: bad bearings

yeah, i was thinkin about your bike.

Man, that sucks.. but i guess it's part of the game. I got lucky and found two replacement motors for my bike and it sure makes me feel better about tinkering with it.. Replacement parts for these old bikes are priceless.

Re: bad bearings

Jason Luther /

ohhhhh the have a price alright

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