Originally Posted by RayJ

I have experienced the same phenomenon with my JL Red Dot. I too tried everything from compression change, pipe change, carb change and couldn't figure out what it was. My front bearing is also in great shape with no signs of any leakage at all.

I also run in Toledo where air temps and barometric pressures change dramatically and we're at 600 ft above sea level.

What Massive says makes sense about the front bearing and it's effects. The motor just doesn't seem to want to draw fuel after it warms up(two to three minutes of warm-up) Each time the motor has done it I had to richen it up about three hours on the top end. This only worked sometimes. Then I changed my clutch and bottom end tuning. I really tightened my clutch down to the point where it was slipping, and then backed it off abit so that it wasn't slipping but kept the motor up in the rpm ranges before engaging. I also richened up the bottom end about two to three hours so that it seemed fat and not where I would normally run any other engine. Running the motor that way I could lean the top end where I wanted it, and it would come into the pits and immediately idle down. It would then leave a healthy trail of smoke leaving the pits initially but would be okay on the track with some smoke and good hard acceleration. The motor has a tendency to really lean out alot after two to three minutes of hard running so a good warm-up before a qualifier is really important.

In conclusion.........running the bottom fatter then normal.........tightening down the clutch a bunch stopped my lean bogging. It sems the motor with a lean bottom and lean top starves for fuel, and the rich bottom seems to help a ton. Hope this helps.