Gearing, maybe jackshaft help. Need 10:1 gear or so

[Night rider]

Hello, I'm new here and need alittle help.

I have a manco dingo 285 Kart that I'm building/modding. I'm using a HF 6.5hp engine on. I know dingo's came with a torque converter setup but mine is missing that and I don't want to buy one.

I want to use a clutch and chain setup. The chain size is #41, new max torque 3/4" bore 10 tooth clutch, 54 tooth sprocket on axle now and stock 18 x 9.5 -8 rear tires (5.4 ratio)

I know with this setup and being a fun kart for dirt, paved, flat and hills in yard I need a gear ratio of around 10:1 to maybe 12:1

How can I get this ratio? I cant seem to find any clutch sprockets for the 3/4" shaft smaller than 10 tooth.

What about a jackshaft setup? I looked at some but most has 14 and 10 tooth sprockets. Thats still only going to give me 7.56 which would still burn the clutch with the big tires

Also one more question about jackshafts. From the looks of it the mounts arfe welded to kart frame and shaft slid in. How do you adjust tension on chain between jackshaft and axle sprocket?

Thanks,
John

 

[r97]

get a 100tooth or 120 tooth sprocket for the rear or get a jack shaft frome bmi karts i think they have a 2to1 rateo

 

[redsox985]

Well, with a 10 tooth clutch you could run a chain to a 20 tooth sprocket on your jackshaft and then on the output end of the JS put a 10 tooth sprocket and run your 54 still on the rear axle. You would have a 1:10.8 ratio. Correct me if I'm wrong but I think this would be a 1:2 ratio between the motor and JS and then a 1:5.4 ratio between the JS and axle giving a 1:10.8 ratio.