I think that inadequate break-in is the issue. Even last year, when I started flying it I was having dead sticks with the engine. I had two airplanes ready (the other had the 75 with similar issues but could be more attributed to the tank being 1-1.5" above the carb) and subsequent to the break in flying, I put in a FS 91sII in that airplane (and lowered the tank). After a break-in I never had problems with that engine. It was damn relaible and ran till it finished the fuel. I am using the same fuel in all engines- klotz with 10% nitro.

My 55 is already mounted at the 45 deg angle, so mounting the 75 that way is no prob. The airplane can take a larger prop- 14x4 in its stock config. I was running a 13x4 on the 55 but had tested the 14x4. If a larger prop is required I will put in a set of larger wheels than the 2" Dubro rubber I am currently using.

I have the following engines lying around

1) 55ax- if I rebuild with a new piston and liner- 18.52oz (525g)
2) 72a- it was meant for another airplane and was bought box damaged. It could be a little under powered as it would be equivalent to a 48 size engine- 18.7oz (530g)
3) 75ax 26.46 ounces- (750g)
4) FS91sII which is a very reliable engine and currently in another ageing airplane. Its lighter than the 75ax (by 2.26oz or 64g) and has a little less power. It will require a rebuild of the Reactor because the throttle servo will not be in the correct place- 24.2oz (686g)

The reason to consider a 65 (about 650gms or 22oz) is simply the weight saving. So if the 65 is required, I will need to order it. Else I will need to take a call and put the Reactor into storage and take out the Phoenix Extra 60" with the 120ax which I am preparing for quite some time


Ameyam