Posted December 01, 2008 - 08:34 PM
gtx, this is just an amateur's observation, but I say it depends. My bike had a terrible bog. It ran better with the choke on, so I figured I'd jet richer. Went to a 48 pilot, 170 main, and a JD low altitude needle at the fifth clip position. Improved, but STILL had a bog, and STILL ran better with the choke on in the low to mid throttle range. I looked into the throat while twisting the throttle and noticed the squirt from the AP was feeble looking. It also wouldn't squirt again without waiting for a few seconds...i.e., the AP housing was taking a long time to refill. I suspected that the check valve between the float bowl and the AP housing wasn't allowing an adequate flow of fuel. So, I found an R&D Powerbowl on ebay and put it on. Don't ask me why, but it has solved the bog AND the need to choke it to make it run better. In fact, I think I am now jetted too RICH, and am going back to the 168 main and will set the needle at the 4th clip notch to see how it runs. Again, I don't quite understand why the Powerbowl has brought this about, but it did. So, for me, I am very glad I bought it. I haven't figured out how the adj leak jet works though. It doesn't seem to make much difference where I have it. The squirt doesn't seem to change.