2 stroke to 4 stroke conversion phase questions

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Crysisfreak7

New Member
May 25, 2014
29
0
0
georgia
If i have the entire kit that came with my 2 stroke engine, and wanted to get a 4 stroke, could i just get the engine and use all the parts i still have, sprocket, throttle, clutch, everything, on the new engine. and if so, would i go any slower or faster with the sprocket that came with the 2 stroke, i dont know if it is 44t or 48t that comes with the 2 stroke.
 

ajoh

Member
Mar 21, 2014
171
3
18
australia
you can but you'll need not only the engine but the gearbox as well an the engine mounting plate
ie, 4G drive or whatever you decide to run

you may need 1 or 2 other things to maybe like exhaust
 

The_Aleman

Active Member
Jul 31, 2008
2,653
4
38
el People's Republik de Kalifornistan
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.
 

crassius

Well-Known Member
Sep 30, 2012
4,032
158
63
USA
so many things are just a tad different that I'd get a full kit for the 4-stroke and sell the 2-stroke stuff (might save you days of mods & metal bending)