97 Craftsman

why are these so addictive?.. heres my new to me tractor



I wanna do a pulley swap in the rear, but I don't wanna go too fast, do you lose much torque with a smaller pulley?

dirtybird wrote:

why are these so addictive?.. heres my new to me tractor



I wanna do a pulley swap in the rear, but I don't wanna go too fast, do you lose much torque with a smaller pulley?

as long as you don't go too small you will be fine , it seems like the smaller you go the more your belt slips, It has a 9-11 inch pulley I'm guessing so if you went with a 4 inch you should be just fine

It might depend on your engine but you should still have plenty of torque. I run 5" engine and 5" pulley with a 16.5 OHV and it put me on my back in 2nd gear when I let he clutch out too fast.

I had my 94 murray as a speed mod - i ran a 18.5HP opposed twin briggs, 6" motor pulley and a 3" trans pulley on the stock 6 speed shift on the fly tranny.

Using a hand throttle ( which i didnt like) - ill say it took a few seconds to 'catch up' - when it did, it was almost too fast to hang on in near stock form. I had it up in 3rd gear around 1/2 throttle, and nearly crashed it - guessing at MPH- faster then my street's posted 30mph speed limit.....

Any smaller then 3", youll slip and burn belts off - isnt enough belt wrap with that small a pulley .

Also keep in mind, the faster it goes, harder it is to control, specially with an unlocked front axle and stock steering .

On my offorad/trail agway i put a 4" motor and a 8" trans pulley on it, not wanting suicide speeds, just slightly faster then the stock 3 speed 'granny gears' ( which i havent tested yet- its still under construction).

Addicitive? Slightly - have 27 tractors, most mow, some are under construction and have like 6 mod tractors in progress ( of various uses).

getting so much fantastic info off this site... I think I might just go to a 5" or 4" pulley and keep the stock one on front..

I have 2 quads and a street bike that hardly get used due to my new obsession with taking this tractor offroad!.. AND CHICKS ACTUALLY DIG THIS LAWN MOWER OFF ROADING!.. lol..

dirtybird wrote:

getting so much fantastic info off this site... I think I might just go to a 5" or 4" pulley and keep the stock one on front..

I have 2 quads and a street bike that hardly get used due to my new obsession with taking this tractor offroad!.. AND CHICKS ACTUALLY DIG THIS LAWN MOWER OFF ROADING!.. lol..

LMAO she thinks my tractors sexy haha can't wait to get mine done!!, have you seen mine yet?

When i was younger the spoiled kid around the corner had an ATC - i always wanted one but couldnt afford it - now im like " Argh- coulda modded a tractor" - never actually crossed my mind to.

The few ive put together havent cost a whole lot, BUT its still cheeper then going out and buying a new ATV - and its something different then the norm. Since i started getting more tractors , id take em down stock into the swamp behind my folks house - i couldnt believe what they could actually go thru and over totally stock.

I want to get phase one of the agway done, so i can see how it rates next to my nephews yamaha 4x4 ATV - phase 2 will be a trans up front for 4x4 mod - using a similar setup to a noma rear steer tractor - sometime in the future id like to build a monster 4x4 tractor from my 90's GT6000 , using all rear tires on it.

have a guestion why does everyone change the rear pulley and not the engine pulley seems like most are runninig 1 to 1 ratio somy thought would be go bigger on the engine pulley would think that would give you lot more surfice area for the belt to grab

just thinking out loud

redneckcarrow wrote:

have a guestion why does everyone change the rear pulley and not the engine pulley seems like most are runninig 1 to 1 ratio somy thought would be go bigger on the engine pulley would think that would give you lot more surfice area for the belt to grab

just thinking out loud

definately a good point, I did change my motor pully but it just wasn't enough speed for me idk bout others

Every mower will be different, I changed both. Mine came with 3" motor and huge(12"?)trans. Some mowers will have a smaller trans pulley, like the MTD's have a 5". On the other hand, the hydro murray has a 5" motor pulley, which is what I'm using.

mine has the stock 9" on the rear, very good point, I'm changing the trans pulley just cause it seems way easier to get at to change...

I was rock crawling mine yesterday and flipped it over, and did I ever beat myself up!!! I need to lose some tourque, tractor is fine, but I'm hurtin today, those bear claw tires will dig & dig untill it flips backwards, but I still have a huge smile on my face, I LOVE OFF ROAD TRACTORS.LOL

Has some math to it ( dont ask me) , but has to do with revolutions of the motor vs the trans and ratios - large motor pulley with RPM range means itll go alot faster , too big tho and it lugs the motor down tho.

Stock tractors use the smaller engine pulley for more power, because its driving both the deck and trans - motor needs to turn faster - the large trans pulley slows it down , with the set gear ratios in the trans - putting a smaller pulley on the trans speeds the ratios up .

Its similar if the tractor comes with small tires, if you put large tires on it, it actually will make it faster, because they cover more ground then the smaller tires - that also changes the ratios.

Sort of like in a car- if it came with 15" wheels, you put 20" wheels on it- thats a 5" difference - that screws up your speedometer and also affects how the car drives - because of the set ratios in the trans and differential - sorta like lil toyota trucks with 44" mud hawgs on em and the stock differentials- things cant get out of their own way.


Depends what youre after, either speed or power - for speed : large front pulley ( id go no larger then 8" - lugs down the motor too much- my 6" has some delay with a twin cylender) and no smaller then 3" ( belt issues) on the trans.

Power : 1:1 - or a bit smaller/larger then stock - front could be an inch or two bigger, the rear a few inches smaller then stock .

Sometimes you just need to experement with different pulleys to get the right combo.....

That is a sweet tractor man. You need a lift and bigger front tires tho lol... Love the bear claws. On my Rally I have a stock front with about 4" rear pulley and she still crawls in the low gears, but putts alog pretty good in 4th and 5th with enough rip to whip donuts running a stock 12HP Briggs and my 25x13" tires lol