I have a Diamond Dust that I had a 46FX with tuned pipe. Ran great until the engine blew. Your repair dept says there is no hope and has offered to replace it for a price with the 46 AX.

I had been told on a different forum that the AX was not as hot (RPM wise) as the FX and the AX would not be a suitable replacement for the FX on the Diamond Dust.

1 What do think?
2 DO you have motor in mind the you would use instead of the AX?
3 Will my tuned pipe from the FX work on the AX?
Thanks

The O.S. Max .46 FX and .46 AX have just about the same performance specifications. Minor differences. You'd notice little difference, if any, by using the .46 AX..certainly not less power.

thanks, will my current tuned pipe off of the FX be OK?

It will work. Just make sure it's properly-tuned for your fuel/prop combination. Tuned pipes must be tuned for each individual installation.

Sorry but 2 more questions:
1 Should i break the engine in with the stock muffler or the tuned pipe
2. I am new to tuned pipes, using the same prop and plane, will I need to re-tune the pipe to go from my old FX to the new AX?

Thanks

Breaking in with the stock muffler is best because you can't lean the engine to peak RPM until it's had some running times. If the pipe's not tuned correctly, you may wind up with a too-lean run.

When you change to different engines, you usually have to retune the pipe system. IF the new engine is runing th esame RPM, then maybe not.