Hi Terry,
It does not take a lifetime to break in an Enya Iron engine
The way I do it, takes about one hour on the bench. This is the break in instructions I follwow :
10 runs of 1 min in a solid 4 stroke with the needle one hair open before it start to burble in 2. Let the engine fully cool before starting again
8 runs of 2min with the same setting
4 runs of 3 min same setting.
5 runs of 6 min with the needle in the same setting but this time pinch the fuel line to sustain peak rpm for 10s, then release the fuel line, wait 10s and repeat pinching process til the end of the 6 minutes run. Start pinching the fuel line slowly and watch the rpm to increase, if rpm goes down you went to far, back up a bit to keep it at the highest rpm it can hold. If you can, measure the maximum sustain RPM, you will notice that this number will improve. If after this process you still notice that the top rpm is still improving do a few more runs like this. If it sags when you fly, repeat this process a few more times. A very few engines comes to tight and these will take an extra 4 full tanks to do the job right. Never got one like this but some friends did.
If the engine is not ran at the peak rpm then it will take for ever to break in and to develop itīs full potential. Many people gave up on Enya engines because they thought the engine was weak, when it is quite the contrary.
With a Flight Streak/Enya SS25 I would try 9x5, 10x4, 10x5, APC 9.5x4.5 and APC 10.5x4.5 to see which I like best, all these prop will work. So far APC 10.5x4.5 seems to produce the best results.
I setup Profile models like this with 4Oz Sullivan RST plumbed for Uniflow and I mount it on the other side of the fuselage, I mean inboard side. This requires you to launch at peak rpm, as the engine will get rich when start flying. The nice thing is that with the fuel tank on the other side it will richen the mixture if the plane pick up speed and when doing the overhead maneuver the tank will be lower and the engine runs stronger.
Martin