Parts are already on the way; I snagged a 17-tooth clutch from OldMiniBikes warehouse to pair with the stock 60-tooth rear sprocket. That pencils out to roughly 3.5:1. The little 3.5 hp Tecumseh will be turning 10.5" tires and I tip the scales at about 150. Am I about to fry that fresh clutch, or will the ratio play nice?
Ratio question
- Thread starter Lethonomia
- Start date
Too high geared. A 12t clutch is more suitable. You won't get good acceleration with what you have. You want to be closer to 5:1. I appreciate the fact that you mentioned rider weight. It means everything. At your weight, a 14t might work too, although that ratio would be too high for most of us 225 pounders. Since you bought it, might as well try it, unless you want to return the clutch unused, or otherwise can't just swap out the sprocket. You didn't say which clutch by the way, and whether or not it burns out depends a lot on that. There's only a bushing on a max torque or clone to wear. The rest pretty much holds together.
You will have top end but a slug to get going. Like Dave mentioned you are better off with a lower sprocket in the clutch. If it is a Max-Torque all you would have to buy that would fit in the drum you have is a 13 tooth sprocket. All sprockets from 13 tooth to 25 are interchangeable in the same drum. Anything below 13 you would have to buy the drum and the sprocket. The bushing only wears while you are in neutral once moving it is turning as one piece of steel. Heat and centrifugal force are using up the lube in the bushing which is why you have to relube when you are done riding for the day and putting the mini-bike away for the evening. While the clutch is still warm drip some 30 weight oil (6 drips on the snap ring) on the end of the clutch and it will wick in re-lubing the bushing and you are all set for the next day. Lubing before you go for a ride is false security because that oil is thrown off the clutch and you accomplished nothing.
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Good info @Jim Donovan !!!