Just bought 2 25 kohlers for a 100 bucks, one runs but smokes and the other is for parts. I plan to replace the rings and valve seals and also a new exhaust. The motor is going on a go devil frame and i also plan on ordering a
9 x 7 Backwater prop for it. The boat is an Alumacraft 14' x 48" riveted flat for now. The go devil has an 18 honda on it now and goes about 20 with just me, battery, gas tank, and with a very worn out 9x3. If anyone has any thoughts, tips, tricks of the trade, or critisism I am all ears and ready to learn.

Service manual is available on the kohler website. Has all the specs you will need. You can order an overhaul kit that has everything you'll need except for the piston rings. I would inspect the bore before ordering new rings just in case you need to punch it out a bit.

I ordered most of the stuff for my kohler from here.

http://www.kohler-engine-parts.opeengin ... it-2416488

I would seriously consider boring it out and making a 27hp out of it. CB you know more than I do about this what is the biggest he could go with that block?

Russ

You can put the 30 crank, pistons, and rods in without boring it. The bore is the same on all of them, 25-30. The stroke on the 25/27 is the same(2.6), longer on the 30 (2.7).

3.385 pistons is about the biggest you can put in without sleeving it. With a 3.120 stroke that will stamp it out to right at 56 cu in. Stock is about 44. The 30hp is about 45.

35 Briggs is 64 ci.

You can probably push close to 1 hp per cubic inch.

Wow, Thanks a lot guys, all of that info is very helpful and appreciated. Thanks again.