Building a mud tractor. Need some advice....

Hello,

I’m new to the lawn mower group, as a kid growing up I used to love driving around on my grandpas old Murray lawn mower. From research it was very similar to a 1984 11/36.

I recently started watching a few mud mower vids and man does it look like fun! The mud mower build I watched was from a guy named Fearlessfront who had a locked 1970’s Sears Suburban with a 10hp? Diesel engine and 25 or 26 inch tall Vampire ATV mud tires.

So I’ve come for some advice in building my own!
First some insight into what the master plan is!

I’m THINKING of starting out with a Garden Tractor since as far as I can tell they are build A LOT stronger. As for transmission I’m thinking of starting with a CVT based tranny but would go with a gear driven over hydrostatic. I will have to lock the rear end for traction and be running large aggressive rear tires. I’m thinking of running some 27 inch tall, 12 inch wide Outlaws a friend has, but would like the freedom to go as large as 30. As for an engine I’m considering a 400cc Polaris 2-stroke ATV engine used for woods racing I have sitting in the garage. In current form it has around 50-60hp up from the stock 35. I’m thinking it would work great with the cvt style transmission As I can easily clutch it for great low end power while keeping the max speed under 15-20 mph.

I guess my big question is on what Garden Tractor I should base this build around. Will these tractors handle the stress and power?

Thanks in advance,

Brad

Yeah Fearless' diesel is a 10 horse. I like the idea of using an old GT because not only are they stronger but they usually have bearing and grease fittings, two things most of today mowers are lacking hence why they tend not to last as long for everyday use. One question though, what do mean by CVT style tranny? Like a a CVT to live axle?

Does the ATV engine have a transmission with reverse?

You could probably put an engine that powerful through a 633 or 2300, but I would use a jackshaft of some sort to gear it down.

Doug Fackler wrote:

Does the ATV engine have a transmission with reverse?

You could probably put an engine that powerful through a 633 or 2300, but I would use a jackshaft of some sort to gear it down.

Yah, I would think the motor would have a trans built into it. it would be hard to run it to a transaxle with a horizontal input because the motor spins forward while the transaxle input usually spins backwards. Would have to turn the motor backwards to get the right input into transaxle, then would have to have a jackshaft in front of the motor to make it work since the ATV motor output for the chain or cvt belt to chain would be exiting forward. I could see a transaxle holding up to the motor if it was the bigger one's. I just wouldn't do any serious pulling with it.
Would have a bunch of gears.

Might be easier to run a live axle off the motor if it has a built in gearbox or cvt.