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ultimatehick

more speed on old Craftsman

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ultimatehick
I was woundering if i put a bigger around pully on the shaft that drives my transmission if I would really go any faster. I am sure that i would lose power but that is not my concern. I just want it to drive up and down the street. If you think that that won't work than what would you reccamend to make it go faster.

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JonetteP
Hi, the bigger pulley might work, but your clutch might not. On the drive end, a 1/2 inch bigger pulley will make a huge difference. It is input vs. out put . I will try to find the book I used in college to figure out the correct speeds. How fast do you want to go? Neal

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PatRarick
This came from an old tractor manual. Multiply the diameter of the drive pulley by the operating speed (RPM's). Divide this by the RPM's of the driven unit to determine the diameter of the driven pulley for the attachment. Altering this formula by dividing by the diameter of the transmission drive pulley will give you the input RPM's of the transmission. Example: If you have a 3" pulley on your engine, and your engine operates at 3600 RPM, your total is 10,800. Let's say you have an 8" pulley on your transmission. 10,800 divided by 8 equals 1360. That is the RPM that is put into your transmission. Let's say that you want to increase your speed by 25%. You would want to increase your transmission input speed to 1700 RPM. You then have to multiply 1700 by 8. Your total is 13,600. Divide this by the 3600 RPM engine speed, and you get 3.777. A 3 3/4" engine pulley will be needed to increase your speed by 25% Pat

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lsenus
Decreasing the size of the driven pulley will increase the revs into the trans. It'sa simple ratio of rotation of the drvie pulley to the driven pulley. The closer to 1:1 you get, the faster you go. If you want REAL speed, increase the size of the Drive pulley and Decrease the size of the driven pulley. Oh yeah, HOLD ON!!

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ultimatehick
Thanks for all of the help. I all ready have 2 simplicities and the reason why i want it faster is so that I can just get up and down my street faster than the neighbors go-cart. I will proubably try to make the frount pully bigger to see if that does the job and if that does not work I will have to make the back one smaller. Thanks again for all of your help.

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