Well it is obvious that kostas1 means glow and not petrol. Here is something that you may don't know. Petrol engines give way more torque. That is the reason he mentioned petrol. That is the reason he is using a 4stroke. From the pics we can all see that he is using an 80 four stroke which is a good choice instead of using ballast to balance to put a bigger engine. Like this he can turn a bigger prop and that doesn't mean neceserilly that he makes it more speedy. He might choose torque instead and definately with his choice will improve landing characteristics, and better response on the tail surfaces.
So if I were in your shoes I wouldn't be fast to judge before I taste.
Happy flyin'
J.R.

P.S. I fly in Greece too, so I would like to inform you that in Greece they have more strict rules than the AMA; since the rules come directly from FAI.