Flabbergasted

[Hydraulic Jack]

Where did you read the article about using at least a 400 main jet? The last thing I want to do is seize a new piston. Thanks, JackM

While 400 might be a bit much for a small carburetor, using a main jet that is too large for the application will not cause seizure. Usually it is the other way around, that too small a main jet will raise internal temperatures, can lead to detonation, won't provide adequate lubrication, and will usually lead to piston seizure. My guess is that if you start with a 400 on a lightly modified 125, it will blubber like a California politician and foul the plug before you get to the end of the block.

A 400 main might be needed if the bike is modified for racing. Check the article, and see if it mentions whether the jetting recommendation is for otherwise unmodified cylinders or for motocross or other high output riding. Context is important when trying to find a starting point for jetting.

[JackM]

Hy Jack, I believe you may have misunderstood me as I was referring to Sterlings comments above. He said he seized a piston when he used too small a main jet, and I don't want that to happen either. CA politicians. You're spot on. Maxine Waters is a good example. Sterling, thanks for the offer. I have a few jets ordered and will give them a shot. You're right about the main jet being easy to get to. I found the Reed Carefully article. Main jet 300 - 400. Thanks.