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Sears twin 18

3045 Views 21 Replies 7 Participants Last post by  searstractorfan
Hi guys i have a sears about 1979 or 80 twin 18 that i am wanting to make a puller out of. What are these engines RPM and how hard is it to get it up close
to 4000 RPM? Paul
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not very hard to do.... most generally they run 3600-3800 to begin with so your close as it is
just use gearing.... i have yet to change a pulley on one of mine.... if high range 3rd kills the motor use high range second.... low range 3rd is just a touch faster then high 1st i've found is high range 2nd doesnt work with the 12's to use high 1st... when i use to pull my 16 high range 2nd was the ticket with 26x12x12
for him to pull high 3rd he'd have to go just a touch smaller on the engine pulley cuz hes running out of power now
No i did not understand all that. you are right on the OD of the tires as i recall about 72+ and about 75.5. What i don't understand is if there was a 6" pulley on the engine and you have already made the tractor faster by tire size ,then you would have to use smaller pulley on engine to slow it back down. If you make the engine bigger like a 6.5 then you are increasing speed??? Paul
hes talking about going bigger on the rear end pulley.... which will make things complicated..... touch smaller on the engine pulley you'll be set i think.... couple boys up here with their vtwin kohlers and p220 onans run high range 3rd gear.... but their in wheel horses also.... the guy running the p220 also had to go to a smaller engine pulley..... as far as the adjustable engine pulley i have noooo clue where to find them.... probably your best bet is find the next size smaller engine pulley
I'm not arguing here, like I mentioned, I know nothing about these machines, just trying to give some insight.
its all good i wasnt either... your theory is right and works great probably
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