4 stroke vs 2 stroke fuel consumption

[Compu-kart]

I've been running 4 strokes forever and recently acquired a 2 stroke 250cc Rotax kart. I was wondering what the general difference in fuel consumption is between the two types of engines assuming the same displacement.

 

[Dan Brown]

Double the rpm means double the fuel. Typically the 2 strokes use a lot more fuel than the 4 stroke karts.

 

[nobozos]

If it's on alky get at least a 2gal tank later Chuck.

 

[jsf74]

Being a LOT

 

[Compu-kart]

I was thinking the 2 stroke rpm is also higher and the gearing is taller. Is the fuel consumption really twice as much as a 4 cycle? Seems like it would be more than that.

 

[twostroketoowoke]

I was thinking the 2 stroke rpm is also higher and the gearing is taller. Is the fuel consumption really twice as much as a 4 cycle? Seems like it would be more than that.

If it’s on gas it’s about the same. KT’s, any of the road course TAG/Shifter motors etc they’re all very efficient on gas. I had a highly modified gas CR125 that was very high consumption compared to a stock one and I never saw my 5QT PRC tank past half empty in a long feature. Alcohol tillotsons on the 2 cycles is where consumption really kicks in, and it’s from the caution fests and trying to keep the motor cleaned out from the insane rich carb settings, not 15,000 RPM’s under green.