Can I increase carburetor size on a Phatmoto 79cc 4 stroke to higher cc?

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Doodles

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Oct 15, 2024
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I have a Phatmoto 79cc 4 stroke can I put a bigger carburetor on that engine say a carburetor that’s for a 125cc? Or even a 270cc?? Reason I ask is I got two new carburetors at Mardens for pennies on the dollar and I’m curious if I can upgrade my carburetor to one of those if it’ll give me one a higher speed or more miles per hour or more power or if it would hurt the engine
 

Tony01

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Nov 28, 2012
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I have a Phatmoto 79cc 4 stroke can I put a bigger carburetor on that engine say a carburetor that’s for a 125cc? Or even a 270cc?? Reason I ask is I got two new carburetors at Mardens for pennies on the dollar and I’m curious if I can upgrade my carburetor to one of those if it’ll give me one a higher speed or more miles per hour or more power or if it would hurt the engine
The function of a carburetor is to provide the correct air/fuel mixture at all throttle positions. Engine power is derived from the parts and fits within the engine itself. A carburetor for a much larger engine will at best need only rejetting, but more likely will not work properly due to reduced intake velocity.

If it ain’t broke, don’t fix it. You could get a little more torque by fabricating a longer intake, better exhaust, shaving the head, advancing timing, pretty much doing all “free” mods. A bigger carb usually isn’t one of them unless the specific engine build calls for it (headwork, high rpm billet internals, etc).