What's the biggest motor you can stuff without fitment problems?

[Dirty Harry]

I was flipping through the 2011 Northern Tool catalog that I got in the mail over the weekend and saw a 35hp Vanguard and a 38hp(!) Kohler Command replacement engines. Would either of these fit in a Max II and Max IV respectively - without having to do a bunch of mods? It would be awesome to stuff that 38hp Kohler into my '04 Max IV. I can only imagine what kind of power that beast would have then!!! Or is it better to send off the 25hp that came in it to someone and just have it hot-rodded? Just wonderin' is all.

[George]

I picked up a rebuilt Bandolero (29hp) engine for $1,000, about $300 less than a new B&S(16hp) engine. It has the same size footprint as a 16hp.

[Dirty Harry]

What I was thinking was to remove the 18hp Briggs from my '96 Max II and the 25hp Kohler from my '04 Max IV, stick the 25hp Kohler into my Max II and pick up either the 30hp or 38hp Kohler and drop it into my IV. The 38hp powerplant looks a little taller, but I could just buy a newer engine cover from R.I. I could sell the 18hp Briggs and recover at least some of the capital used to buy the bigger Kohler. What's the biggest mills that R.I. is stuffing into their machines nowadays?? That 38hp Kohler would sure make my IV one hellacious monster. I'm just worried that it might by too much power and overstress the T-20 and driveline components of the machine. I wanna have fun, but I don't wanna be breaking everything else inside my buggy.

[wfo]

What your looking at is a big block and a small block..center of crank shaft is higher on the big
block and the shaft is bigger...so if going to the big block you will need a diff. Clutch and belt
and possably redrilling where the engine mounts to engine bracket..does that make sense..

[racerone3]

I'm currently testing a small block briggs that is right in the 40hp range. I'm not going to give any contact info till I'm totally satisfied, but this builder will take your small block in on trade. after the Busco Beach ride in a few weeks, I will post the thumbs up or thumbs down on this engine. It was a good bit cheaper than a Bandolero, and would be even less with a trade. If you swap anything with different dimension, you will have to do a bit of fabrication, and possibly clutch change to make it work. I'm not up on Kohlers, but the small block briggs (14- 23hp) all have the same basic dimensions. (25 might also be a small block)

[George]

I'm currently testing a small block briggs that is right in the 40hp range.

Hmmmm...interesting.

[Bonewerx]

Ive got a 570cc yamaha snowmobile and it has like 80ish hp twin carb 2 stroke would that be overkill in my 89 max 2? I wanna be fast but not breakin **** lol idk whats in it now ive never seen this motor in a max but was told its a 440 35ish hp

[jerseybigfoot]

80 hp at 8500 is just about right, but in a 89 max2 that would be a bit much for trail riding and reliability. 35hp 4 stroke would be perfect.

[6X6]

Overkill (I think?) Put an Exciter 570 in his project 6x6.
From what I could find the T-20 should handle it, not sure on
the jackshaft setup on a Max II but I would think probably not
an issue either. Use good USA made chain. You'll go through cheap chain like water.

[Robinhood02]

yup most of the high hp engines are too tall for the Max II ,the biggest that i have found is a 28 hp Subaru that they make in a low profile, i believe that it will fit in a Max II but haven't tried it. and Subaru makes some darn good motors !!! as far as the Max IV i think with little effort you could put almost any size motor in it, 2 or even 3 cylinder, i think the MAX IV is pretty much limit less

[Stonewall]

Subaru makes some darn good motors !!!

Be careful with some of the smaller single cylinder Subarus. (maybe twins too?) This may not be relevant to the larger HP Subaru motors, but my mom bought one of those leaf shredder/vacuums that hooks on to a lawnmower deck with a 9.5 Subaru. After using it about 3-5 hours, the flywheel nut came off. The loose flywheel sheared the woodruff key on the crank, and damaged some of the magnetic pickups in and around it. The company sent us a replacment motor and the same thing happened on it too. It didn't cause so much damage on the second motor, and I was able to fix it by putting some locktite on the nut. I think that the whole problem could've been solved by using a left-hand threaded flywheel nut instead of right-hand threads, as well as a more sufficient key. In my experience, and quite a few people I know would agree, a Honda engine would be a much better choice than a Subaru.

Just my 2 cents

[6X6]

Was this the "Robin" line of motors? I've seen them on various equipment and wondered how they rate. Just curious.
I've had just fine luck with Briggs, while some of my friends would rather operate a hand-crank than a Briggs motor Not that I've had any issues with Honda that I could fault Honda for.

[Bonewerx]

Mines a 570 exciter also and the top of my body over the motor is gone so height is no issue im really debating on putting it in but idk what clutches to use or anything and idk if I wanna tear the snowmobile apart yet jus some debating lol can anyone find my "what motor is this" thread and try to help identify what that damn thing is lol

[phil_1066]

There was a Max on E-Bay last year with a motorcycle engine plus gearbox fitted. I am sure I saved it somewhere. If I find it I will post it up. I have a spare BMW 1150 Gs engine..... wonder if that would fit?

[LarryW]

Those are all little motors, The biggest engine that fits is probably that 4 cylinder pinto engine Shanna/KevinGriffin have in there max. Think its a 2.0l? They did have to cut some of the back of the top off to make it fit, like I think the whole back of the top, lol.