Engine rebuild

I have a 14.5 HP Quite IC engine that I want to build into an off-roader. Briggs & Stratton model number 287707 Type 0224-01. Trying to find out if this engine is a good choice and what would be the best mods for rebuild. Carb, cam, and what ever else anyone can come up with. Thanks for any help.

Thats one of the best to use IMO. Just a cheap Mikuni clone 28mm slider carb and a governor delete are all thats really needed. i would estimate power with those mods around 18 hp. Anyone else?

If you wanted to modify the internals of the engine, shiming the head a bit to increase the compression and welding on extra long lobes onto the cam. If you'd prefer not to dive deep into the engine, I'd suggest maybe filing the flywheel key to advance the timing (slightly) and carb/governor removal etc.

I have a 15hp (model# 28n707) and all I did to it was a little porting in the head and polished all of the journals and bearings. It runs good but I'm not looking for any serious power. On top of what I did you could try decking the head for some compression and a diff carb/governor

Is this the carb you are referring to ? Mikuni TM Series Flat Slide Carburetor (VM28-418) - 28mm .

That would work fine yes, but I was referring to the round slide. And the genuine Mikuni is quite expensive. A cheap knockoff is about 30 bucks on eBay and works just fine

You'd need to weld up a manifold for that slider carb.

I used to modify old genuine Honda 5.5 and 6.5hps for racing/rallying about in fields. The basics really are, more fuel and air in, more power out. I'd suggest right away that you pull the head and clean the carbon as that can effect performance quite badly in my experience. Another thing that hasn't been mentioned yet is a straight through exhaust. The baffles on a stock exhaust are usually pretty restrictive so if you can let the exhaust gases leave the cylinder quicker, then you'll get more power.

With the engine he is using, he can use the stock OEM manifold. He just needs to take a rat tail file and widen out the hols a little, not much to it.

I ordered the round slide Mikuni off ebay yesterday. I will clean the entire engine when I tear it down later this fall and will pay particular attention to the head. Now trying to find a rebuild kit for the carb. It came off a John Deer Spitfire Kohler 340. I cant seem to locate a kit for it though because I can't find the year model of the snowmobile it came off. Its a 28MM though, if any of you guys can make a suggestion on a rebuild kit please let me know. I will work on the exhaust upon rebuild as well. Thanks for all the suggestions guys, it's just what I needed.