gearing ratio

[Nic]

we have a vertical drive engine (11hp) and the diff that both came off a riding lawnmower similar to this one here.
the diff is approximately 1:4 ratio and the wheels came directly off it, so it would have plenty of torque. i am asking whether i could put another gear ratio coming off the diff to another axle (similar to ryf's car.) would there be enough power if i put a 1:1.5 or 2 on it?
cheers

 

[RobertD]

Hmm, that's a good question. But I like the idea of changing the power after the differential... That could be the "weak link".

 

[2or3wheels]

I dont know. The more RPM's your engine goes the faster the wheels will spin.

 

[Nic]

yea
the wheels should spin at around 900prm @3600 rpm from the engine (full bore), that should do 50km/h with 30cm diametre wheels.. It should have heaps of power, but if we geared it up by 1.5 X i think it will have enough power as 1.5 times isn't very much.
our engine is an 11hp.