WILL OS 70 SURPASS POWER A 60 SIZE TRAINER WITH ANY AUTHORITY?
THANKS

Ray, an FS70 is typically used in place of a 46FX. It is actually more powerful than the 46, but the 'flavor' of power is different.

I can't say without knowing more about your trainer, but in general, yes, the FS70 will give you sufficient performance on a trainer model designed to be powered by a 60FP.

I have 2 OS 70 Surpass engines, and both have done many 100s of hours. I am extremely happy with their performance. I have several times decoked them and ground the valves in.
I want to purchase a replacement and my question is "What is the difference with the OS 70 Surpass mk11?" Do I buy one of these or another original one? I want to assume that the new mk11 is superior in performance, howevere the BHP figure of 1.1 is the same for both. I see that the mk11 has a new carb, is this where the difference is?

Nosram, A variety of parts are changed in the MK II. I would suggest looking at the two exploded views to compare them part for part to see if this helps answer your question. IMHO, the MkII is even smoother and more reliable in performance.

Thank you amcross for the advice, I guess the mk11 is the way forward. Shame the throttle is in a different place however. I have looked on Great Planes web site, OS, Tower Hobbies, and Hobbico and haven't been able to see an exploded view. Can you help please, thank you

My apologies, looks like the new engine's view isn't posted quite yet:
http://www.osengines.com/parts/exploded-views.html