I converted a TT 42 and a TT 46 from RC to CL several months ago.  They are both great RC engines especially considering the price.  They both run well but with dif problems.  The 42 has a tremendous 2-4 break, much more than it should.  The 46 on the other hand seems fine for the first part of the run but the last half it actually slows down when going into a manuver.  I've been told that I should add an additional head gasket to the 42 which I haven't done yet but Have no idea what to do with the 46.  I was flying it today on a Cardinal with 65 foot lines and it has plenty of power until it starts slowing down.  Any suggestions.

Sam

Reducing compression and/or Nitro should help the .42. The .46 sounds like a fuel tank problem, like a cracked tube inside.  Steve

The reason I asked about the tank, I have noticed that my ST 51 with metal uniflow tank runs several laps slightly rich at the end of the flight. 

I have been told this is characteristic of uniflow tanks.

Jim