Four stroking

Discussion in '2-Stroke Engines' started by ilovenxtage, May 15, 2013.

  1. ilovenxtage

    ilovenxtage New Member

    My engine has been "four stroking" a lot. I've read that four stroking is caused by the mixture being too rich. However, I have set my needle C-clip as lean as it will go, and it is still four stroking, except when it's under heavy load, such as going up a hill. There doesn't seem to be any obstructions in the air filter or anything like that.

  2. Anton

    Anton Administrator Staff Member

    I have exactly the same problem. I have my c-clip set to lean and the bike runs perfect up to 3/4 throttle. Then from 3/4 to full throttle it 4 strokes. Although I haven't fixed the problem yet I know what to do from reading on the site. Basically from 3/4 to full throttle the needle no longer has any effect and it is the size of your jet that determines the amount of fuel getting sucked into the bikes engine.

    What you'll need to do is get some different size carb jets. The stock NT carb on these engines has a 0.70mm jet I believe. From reading, people have had luck with a 0.66mm. They are only a few dollars each so you can order a few different types if you like.

    To change jets all you need to do is remove the float bowl from the carb (the bottom part of the carb) and then unscrew the jet!