Johnny 5
12-07-2010, 12:22 AM
Just swaped a older cam from our broken valve 2004 150cc baja dune . The newer motor we bought in 2/9/09 was a scooter motor for $249.00. After I put the new motor in I thought it was a 125cc. The power was weak and it idled too smooth. I checked the motor #157qmj and it is a 150 cc. I checked the carb main jet it was a 103 and pilot 34. So I thought I had it figured out I put the 115 main jet from the origonal carb and it still was weak same idle, smooth great response and take off but no power on top. I thought that the valves on the newer motor are smaller causing the lack in power. So before pulling the head I swaped the cam from the older motor to give it a try. As soon as I started it up I could hear the motor was deeper in tone and had to turn up the idle. On the first test drive there was a noticable difference in power. Almost 2 years have been trying to figurue whats up with this motor. I believe that scooter cams and buggy cams are diffferent, by the weight factor. Cant wait to hit the dirt.