97' cc ds 10" lifted 420cc pred swap gears and cvt gear ratio combination

[Lilcountrydriggers]

Hello i have as a cc project that I'm trying to gear right. i have 26" tires 6.25:1 w/16t on axle, 420cc has 780r from vegas carts, 780 driven 9.25 on jack shaft going to drive sprocket of (10t or 12t?) Wanna try and get the right sprocket if anyone knows ratio or how much low ill need for choosing which sprocket or changes ill need to be a torque and decent speed 25-30mph sounds fun. Engine has no mods but plan on jetting and springs afterwards ..any help appreciated in advance

[Lilcountrydriggers]

Also if needed the axle is a 86' ezgo textron i had to get the counter clockwise and clockwise of the drawing board:)))

[sho305]

You can look up your axle to find gear ratio, then use a speed calculator on the net where you enter the gear ratio and tire size and rpm you run. Most stock carts are 1:12-1:13 trans ratio stock. If you go 18 to 22 tires that usually gives you about 8mph more. So say your stock or lawn engine with no governor can run 4300-4500 flat out that is about 20mph or 27-31mph with 22 tires and 15psi in them, in my experience with G9 yamahas using a gps. However don't forget most carts run CVT will overdrive in case of Yamaha that is .9 so at full shift the .9x13 ratio comes out to about 1:11 total when you use a calculator with engine rpm and tire size (diameter). Now if your engine only does 4K rpm on a governor or 6K rpm with a big cam in it, that is also going to change your speed. If you run 8:1/6:1 gears on the road you wont want to have engine screaming, so you want to hit a nice cruise speed at say 3K rpm or something for a stock engine. More gearing hurts torque for hills and towing of course, but larger engine has more torque to start with.

Your gearing is going to be really high if you have 26 tires and 6.25 rear end (if I understand correctly what you are doing), both will get you more speed than a typical 22 tired stock cart. The 780 clutch will likely have similar ratios to a stock cart. What you may want is what a 8:1 cart does where 25mph is calm rolling and 40mph can be hit with a stock or near stock engine. So that is a 7.5(including cvt) to 8 (actual gears) ratio gearing + 22 tire size + 4K = those speeds. Put those numbers in and change to your ratios, then change your sprocket to get similar overall speed/ratio. So technically you would need to drop about 2 to make your 6.25 be an 8 ratio, so start with sprocket that will drop ratio 20% and see how that stacks up, the rear sprocket being 20% more teeth than the driven sprocket. May have to adjust one way or other. Then compare to a typical HS gear cart is: .9 overdrive plus 8:1 trans plus 22 tires and see if its close. That is a common setup if someone puts a stock twin lawn engine in that can run say 3600-4K rpm. I think I got that all right lol.