I am a team driver for Mugen and Ninja in the UK and have run the new MRT engines for the last 2 months and found the following:
1) Version 1 batch number: 0017921. Piston and liner run in similar to the standard engines. It was very tight to start with but then after 1.5 hours it was OK. We found that when leaned on the top end needle, the bottom end would run on into corners. To prevent this we richen the bottom end up to prevent it sounding lean. The needle is a 1.82mm out of the linkage bezzel. On the bench it smokes a lot and feels slow to pick up, but once on the track and up to temperature it feels OK. The temperature on track is about 120-130deg C. I am using Runner Time fuel.
2) Version 2 batch number: T-001086 02. Piston and liner very tight and still needs more time after 3 hours and run temp of 130 deg C. When leaned out at top it runs high when you throttle off into corners but a quick blip in the pits will allow it to idle as per normal.
I then tried changing the head on this engine from magnesium to aluminium and it was now not running high into corners. I feel that this is not a true reflection on this engine since it is still running in!
With version 1, I am impressed with the increase in bottom end power and I can easily do 5 minutes with the fast link pipe and small manifold.
I would like to know if Mike Swauger is experiencing such problems and what the the solution is, if any.