Kohler Command 18 HP engine

[chris lewis]

All,
I decided to sell my Max..but could not do it. I have fought for a long time with my JLO 440 and could never get it running right. Turns out that I MIGHT be able to get a brand new Kohler Command 18HP twin cylinder with a 1 inch Output shaft from work for close to (or possibly) free.

So my question is this: What clutch (driven and driver) would I need and what would I need to do for an exhaust? There is no exhaust on it as it sits now. I do have the old JLO 2 Stroke exhaust but would need to make an adapter and manifold etc for the Kohler engine.

Thanks!
Chris

[jpswift1]

The driven clutch would just need a 4 stroke spring installed (green or red) which you can get cheap, directly from Recreatives. Amphibious Six-Wheel Drive All-Terrain Vehicles: MaxATVs - Call 1-800-255-2511 The 4 stroke 1" drive clutch is a little expensive, but I have a nice working used one for sale that is specifically used on the Briggs and Kohlers from Recreatives that I just put up for sale here:

http://www.6x6world.com/forums/parts-sale/26690-comet-780-4-stroke-1-drive-clutch-175-a.html

The exhaust can be done up custom, or you can get a stock Kohler muffler off ebay and make some slight alternations to it to make it work on your Max.

[chris lewis]

I will find out on Monday whether or not I will get the engine...so I will have to wait for the purchase. Hopefully it will still be available.

Thanks
Chris

[chris lewis]

I did end up getting this engine and bought a new clutch for it (Comet/Salusbury) 780. I put the engine down in the tub and here is my new set of questions:

The top of the air cleaner hits the body and holds the body up about 3 inches. It appears that even if I remove the air cleaner and remote fit it, the tub area on the MAX II is quit low and also seems to hit the engine.

What have others done to modify their Max upper tub? Cut a huge gaping hole to fit the engine? That seems the only viable option even with remotely mounting the air cleaner?

Also, are there ducts to redirect the cooler air to the fan/recoil? I have to remove the steel coool air duct from upper tub (which supplied cool air to the engine from the opposite side of the body.

Also, are you guys running isolator mountsor hard mounting the engine to some type of engine mount assembly?

Thanks for your help.
Chris

[thebuggyman1]

The "cool" air duct you removed is actually a "HOT" air duct. It directs the motor cooling air out of the tub. This is more important than the cool air duct because the hot air ingested into the air filter will reduce engine HP. Some people have actually partially melted the upper body from too much heat in there.
When I put the 40hp Kohler in the MaxII Bigfoot/ tall tub - Amphibious ATV Pictures I had to cut the top all the way out, but I'm sure it is much larger than the 18hp. It will also generate much more heat.
The rubber isolator mounts are not needed. I had nothing but problems with them "giving" too much and messing up clutch/belt advancement/upshift. Your maxII should have a motor mount plate.

[ARGOJIM]

http://www.6x6world.com/gallery/data...dium/max32.jpghttp://www.6x6world.com/gallery/max-...b-ii.htmlChris, you'll have to make a new engine mount plate as yours is probably still the curved 2 stroke mount. What color is your body? You may be able to find the later hood cover and cut the larger opening that is about half way across the upper body and still look factory.
Look in the Max gallery there are pictures of the hood I"m talking about and some pictures of others engine mounts, you could also get a set of mount from RI and fit them to your frame.

[chris lewis]

Hi ArgoJim,

My body is red. I was going to make an engine mount similar to the old style (14 ga angle slotted for adjustment but then attach two /12 inch rectangular bar stock perpendicular to the angles, drill and tap those to accept the engine. I cahnged my mind on that and am considering using a 1/4 inch steel plate, same length but wider width, slot the four corner holes similar to the original but then put PEM studs through the plate from the back side and bolt the engine to the plate that way.

The plate can slide fore and aft but the left to right will not be able to move...so my mill/drill/tap will have to be accurate such that the belt/pulley geometry is correct.

I looked through the gallery trying to do a search for engine mount, repower, mount etc. but came up empty handed searchwise.

Do you recall any particular member who has done a similar modification with decent shots of their engine mounts?

Thanks
Chris

[ARGOJIM]

Chris I've looked around and can't find the pic I was looking for but it's out there. I'm making my mounts like the newer mounts 1/4x2-1/2 flat stock slotted in both directions, will post pics once done. The older machines frames are slightly different needing the mounting frames to be 1-1/4 longer to meet the frame correctly. Years ago I hard mounted a tecumseh in a max2 measured a few times and drilled some holes, it worked fine for the 2 years I owned it and more for the next owner, if it's not straight it'll tear up belts.