hi again,,
thanks for the reply..
ive never really had a novel from brand new as the 1st engine came with the heli 2nd hand (which ran qite well for a small engine ) so i havnt needed to run one in..the replacment engine i got for it was also 2nd hand but it has good compresion..it was a slighty bigger engine too..
the strange thing is that the fuel i used for the 1st heli engine worked very nicely with that but then with the 2nd engine i found it was hard to keep the engine running once started which made me reluctant to fly to high incase the engine would stop..but when i tried the 30% fuel in the 2nd engine we knowticed how much more the engine liked it and it used the whole tank of fuel each time..
so when i say i think fuel is criticle i mean more the nitro content rather then the fuel oil type ect...

ive not realy had a problem as such to start the engine as i find for me at least the easiest way and most efective is to use and electric start on it without priming,but as the engine is being turned i very briefly put my finger over the air intake so i can get it started from hot or cold in seconds..(i dont recomend that mehtod to all pilots but me n you have had a few years experience with engines to know when we should take the finger off ofcause )..
i might have a look at the new engines perhaps..i run my engines in most of the time with a prop too,just depends if i ca be nothered to do it on a test bed,else ofcause id do it in the heli but as you sugest it might be better to run it in with a prop..

i think cambo and i ofcause are mostly comparing these engines with other engines of its size because there are other engines of the same size that dont need such ataintion/hastle to get to run well.