12-05-2001, 09:16 AM
I have been reading alot of guys running 155 and 165 main jets in basically stock bikes with bolt on stuff. I don't know what to think but here's my story and my dilemma.
My 400ex has a K&N air filter with stock air box/ snorkel setup, a White Bros. E-Series silencer, and I ride in South Jersey. I changed my main jet to a 155 and found I was using twice the fuel and she was bogging on the top end. So I went down to a 150 main and it was running OK with almost normal fuel consumption. I then purchased a Dynojet jetting kit and installed same. The needle is in the stock C-clip position (3rd notch) and the main had the Dynojet emulsion tube with a Dynojet 146 main jet. Shortly after this change I also installed a Pingry oversize oil tank, claiming to lower the operating temp of the engine because of the added oil capacity and the tanks cooling properties. This setup ran well, but on extended rides I was still running out of gas first. I changed the main to a Dynojet 142 and the bike runs great but I'm afraid of being too lean and doing some damage. The bike doesn't break up when wide open and pulls strong, but I notice a louder exhaust note, almost as if I had increased the compression. Give me your opinions...
My 400ex has a K&N air filter with stock air box/ snorkel setup, a White Bros. E-Series silencer, and I ride in South Jersey. I changed my main jet to a 155 and found I was using twice the fuel and she was bogging on the top end. So I went down to a 150 main and it was running OK with almost normal fuel consumption. I then purchased a Dynojet jetting kit and installed same. The needle is in the stock C-clip position (3rd notch) and the main had the Dynojet emulsion tube with a Dynojet 146 main jet. Shortly after this change I also installed a Pingry oversize oil tank, claiming to lower the operating temp of the engine because of the added oil capacity and the tanks cooling properties. This setup ran well, but on extended rides I was still running out of gas first. I changed the main to a Dynojet 142 and the bike runs great but I'm afraid of being too lean and doing some damage. The bike doesn't break up when wide open and pulls strong, but I notice a louder exhaust note, almost as if I had increased the compression. Give me your opinions...