GSX250 go kart questions

[tomas02]

Hi
OK so i have a GSX 250 engine 1990 version and it has a 14 tooth front sprocket with #520 pitch
want to know what size rear sprocket i would need so the top speed is about 100km/h
I can't find a max output rpm of the motor which is why I've told you what it is
Thanks

 

[JHen]

What size tires will you be using?

 

[Doc Sprocket]

To calculate it out, you need the engine's max rpm, the final transmission ratio. If you can't get this info from a spec sheet somewhere, your next best bet is to grab the bikes original rear sprocket and count the teeth. That's a good starting point. The bikes original ratio would be a bit high, but odds are good that your projects rear tires are smaller, effectively lowering the ratio.

 

[tomas02]

forgot about tyres
rear tyres are 16 inch diameter
and unable to find max rpm or final transmission ratio
anyone know where i could find that
also i dont have the original sprocket just have engine

 

[Doc Sprocket]

Google your brains out, there's gotta be some info out there.

 

[JHen]

http://www.suzukicycles.org/GSX-R-series/GSX-R250.shtml

 

[tomas02]

Hi again
have found this page http://www.scribd.com/doc/413315/Suzuki-GSX250F-Service-Manual
which has all the gear ratios says top gear had a ratio of 1.227 (27/22)
and the engine does 15000 rpm
what would that make the rpm of the output sprocket?
do i just do 15000 x 1.227?

Thanks for all the help so far