tractors with push mower engines

I was just wondering who here has tried putting push mower engines, 8 hp and smaller, mainly in the 6.25 and under range, on a tractor?
ive seen multiple pictures of these and a video or two but wonder just how much power one would have. not for mudding but just offroading. maybe step hills and suck. to me a small push mower Briggs engine is more reliable than any lawn tractor engine (in my experience) and i want something reliable on the tractor im building more than something powerful

if you have done such a engine swap, please post pics and links to threads if its on here down below. Im very curious!

It's all in the gearing. You could get pretty much any engine to work on a tractor if you work the gearing right. If you kept the stock pulley sizes a push mower engine would be fine. You would have to drill a slightly smaller bolt pattern for to bolt the engine down though.

Chevy8988 used a push mower engine in his Frankenstein racer, and it worked fine.

You can make a 1/2 horse engine pull a train, geared right....at about an inch per day.

Now this obviously won't be as extreme, but you won't really be getting anywhere fast. At least not without starting in low gear and shifting up as you go.

Agreed. My old walk behind tractor has only 6.6hp, and it's a ground engaging machine. It's not all about power, you gotta get it to the ground too.

i figured they would do pretty good on one. thing is i already pulley swapped my tractor project so it would be harder on the small engine to pull it. I think i might put one on the racing mower i plan on making this winter if i can find a decent one somewhere

It depends how my HP you're push mower engine is. If it's a little 3.5hp Briggs then it won't do much more than stock speed, but if it's 5/6 then I'd say you'd be able to do at least 15-20. If you think about it, my 5.5hp go kart can do 35mph and it's got a pretty heavy tube frame.

MatthewD wrote:

It depends how my HP you're push mower engine is. If it's a little 3.5hp Briggs then it won't do much more than stock speed, but if it's 5/6 then I'd say you'd be able to do at least 15-20. If you think about it, my 5.5hp go kart can do 35mph and it's got a pretty heavy tube frame.

thing is im a big guy and i want to take it on some steep places on my farm. a really small engine pulley with a stock tranny pulley would work fine i would say. doesnt need to be fast anyway. low end torgue (what little there might be) and slow, crawling capability is what would be best

If you start off in 1st gear and change up 1 by 1 to 5th/6th whatever your top gear is, you could get away with less HP and if you wanted to climb hills, you just change down into 1st/2nd. What kind of HP Push mower engine are you wanting to use?

I've put a 6.5 pressure sprayer motor on a Troy Bilt for the kids to play on. I'll post a pic when I can. Had to drill new holes for it is all. Even running same size pulley. Just have to make sure not in a high gear or floored on vari drive when trying to climb hills or such.

mightyraze wrote:

I've put a 6.5 pressure sprayer motor on a Troy Bilt for the kids to play on. I'll post a pic when I can.  Had to drill new holes for it is all. Even running same size pulley.   Just have to make sure not in a high gear or floored on vari drive when trying to climb hills or such.

that would be a nice idea:
putting a stock 5 speed or 6 speed in a vari-drive tractor with a push mower engine
simple, cheap
i might do that if i get another MTD sometime

I got a riding mower with the vari-drive and changed the f/n/r for a 6 speed. The transaxle pulley is about 4 inch with the original engine pulley, and an 8 hp Briggs on it too for the pull start. Goes real slow, I used to use it for cutting grass. I had to slow it down because the 8 hp wasn't strong enough to cut the grass. Works good for cutting the grass now that it can go real slow.

Yah, so I got 36 forward gears and 6 reverse gears on it, LOL.

I almost bought a sears suburban. it was a 70, if i recall correctly. the original engine had gone, due to neglect. it had a single cylinder, not sure who made it. not an onan. But somebody had repowered it with a 3hp briggs single and slightly changed the gearing. He used it as a utility tractor, said it would pull his full size 2 ton utility truck. Kinda impressive. but you can do a lot with gearing. He said it was slower than watching a non turbo 7.3 diesel with a manual accelerate, but man it could pull. in the end, he would not budge from his price of 200 bucks, which in my opinion is too much for a rusty, beaten up tractor. The entire thing looked like it had never been kept under a roof its entire life. Too bad, i like me a good ol sears....
Anyway, thats just my two sense

prancstaman wrote:

I got a riding mower with the vari-drive and changed the f/n/r for a 6 speed. The transaxle pulley is about 4 inch with the original engine pulley, and an 8 hp Briggs on it too for the pull start. Goes real slow, I used to use it for cutting grass. I had to slow it down because the 8 hp wasn't strong enough to cut the grass. Works good for cutting the grass now that it can go real slow.

Yah, so I got 36 forward gears and 6 reverse gears on it, LOL.

that sounds like it would be fun to putt around on lol
i tried putting a 8 hp on a 38 inch craftsman 2 and it didnt turn the deck good. it would ride a wheelie but as soon as the blades were engaged it would bog down a lot :/ i would have thought it would have worked on it but it didnt
ive got a 8hp but to me a briggs push mower engine is a lot more reliable than a riding mower engine for whatever reason :/
thats why i prefer Kohler over briggs
briggs and Tecumseh are about on the same level for me

mightyraze wrote:

I've put a 6.5 pressure sprayer motor on a Troy Bilt for the kids to play on. I'll post a pic when I can.  Had to drill new holes for it is all. Even running same size pulley.   Just have to make sure not in a high gear or floored on vari drive when trying to climb hills or such.

Here is the one I mentioned above.

Nice mower man. Does it do stock speed?

It does a little over 6mph.

mightyraze wrote:

It does a little over 6mph.

omg dude xD
that thing looks awesome
i hope i come across another MTD sometime so i can tranny swap it and do something like this lol

You could probably push more than 6mph out of her. Mower looks really cool

I was thinking the same. Swap a couple pulleys and it would be faster. It's good for now.

Yeah, I think that there is a place for small engines in the off road mower world. Too often you see those big 24hp V-twins installed when you're never going to use all that power. A small engine also means higher fuel economy.