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Old 08-06-2014, 07:52 PM
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The_Aleman The_Aleman is offline
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Join Date: Jul 2008
Location: el People's Republik de Kalifornistan
Posts: 2,658
Default Re: 2 stroke to 4 stroke conversion phase questions

A chinagirl has a 4.1:1 internal reduction and most 2-stroke kits come with a 44T sprocket, those end up being 18.04:1 overall.

You'd have to figure out what 4-stroke kit you'd be getting to find out what new ratio you'll have, and to find out if your 44T will work for you.

Kits with Q-Matic average about 2.76:1 at output
Kits with pocketbike gearbox average about 3.25:1
4G is available in 4:1 and 5:1 output

A small 4-stroke will need a numerically higher gear ratio (>15:1) for best performance. A 79cc or higher 4-stroke can get away with a numerically lower ratio due to torque.
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