50cc rebuild/upgrade problem

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Coosie

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I have a 139fmb 50cc 4 stroke 4 gears semi auto electric under/kick on a mini chopper. Piston and cylinder and connecting rod bad. Ordered a new crank didn't realize it was a 49.5mm stroke till after I installed it when the 39mm piston pop out the top of cylinder.what would I need to get to make this approx a 110cc engine and where? Not much luck finding a 41.1 stroke crank.
 

dirtbkr188

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1. A 69mm tall cylinder
2. 4 longer engine studs
3. A longer cam chain
 

Coosie

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1. A 69mm tall cylinder
2. 4 longer engine studs
3. A longer cam chain
Thank you for the response. Any idea for a source for these parts in the USA. and would I need a different head. I'm assuming the 69mm tall cylinder would be 52mm bore.
 

dirtbkr188

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A 52mm cylinder would give you 105.12cc and a 54mm cylinder would give you 113.36cc. You can find those cylinders
HERE and HERE, the engine stud/cam chain kit is HERE

You'll also need the piston kit, gasket set, and a different head, as you mentioned. Those parts can be found HERE as well. Beatrice Cycle/DRATV is located in Nebraska
 

Coosie

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A 52mm cylinder would give you 105.12cc and a 54mm cylinder would give you 113.36cc. You can find those cylinders
HERE and HERE, the engine stud/cam chain kit is HERE

You'll also need the piston kit, gasket set, and a different head, as you mentioned. Those parts can be found HERE as well. Beatrice Cycle/DRATV is located in Nebraska
Thank you so much. You made my day.
 

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