I just finished my first tank of fuel in my 23cc Baja. Dang, I am used to 15 minutes tops with my Revo 3.3, but 42 minutes to empty (I killed it as soon as the fuel got low enough to lean out the engine)? I know it was my break in tank and I was taking it easy but good lord!!!
So far my engine is running like a dream. I think the main reason people have engine issues with the KM or any Baja engine for that matter is lack of tuning experience. I have been creeping Baja boards for the last week waiting for mine to show up and have learned a couple things.
First and Foremost, CHECK THE NEEDLE SETTINGS!!!!!!!!! Mine were way off, the HS needle was out 2 3/4 turns and the LS needle was set to 1/2 turn out. This would have almost ensured a dead motor after the first tank.
Use a high quality 2-cycle oil. I picked up a new 1 gallon fuel can and a quart of Lucas Semi Synthetic low smoke 2-Cycle oil for 17 bucks at my local Napa store. I mixed it a tad rich, 24:1 rather than 25:1, cant hurt having a little extra oil on break in. I would rather smoke a plug than a piston!!!
Go easy on your first tank, no more than 1/2 throttle and don't hold a constant speed, vary it from idle through mid rpm, feather the throttle. You need to break the ring in and have it seat a pattern to the cylinder wall.
If anyone thinks I am wrong or has something to add, please chime in.