Hi Mark,
I'll be honest mate.
Sell it.
It's designed for a glow engine.
I did the same mistake.
I had a DA 50 on mine with a standard muffler. Tons of power but when of throttle all hell broke loose. The wing loading is just not there. I would not agree with mbartsch (no offence mate) that it flies like any other yak. It flies NOTHING like my QQ Yak 86 or even the dirt cheap League RC Yak 54 that I have as a throw about. It also came always heavy and fast for landing, needing twice reinforcement at the landing gear plates. Flew pretty well KE. When on high rates it would abruptly snap.
If you decide it's a keeper just make sure to mount the rudder servo inbound as it's coming out a tad tail heavy with it mounted aft. Reinforce the LG beforehand as well.
All the gear is out of mine now waiting to be put in the EF 88.5 Extra I'm waiting. I guess it would be perfect with a 160 glow but I just can't go back to such a large glow.
These are my thoughts on your dilemma.
Sorry for my english, not my native language.