Hey guys haven't been on in a while but got a new p-51 60size and I'm going to be changing from four stroke to the g20 zenoah gas engine. This is my first time with a Gasser and I'd like know if you all have any advice from the change. I wont say I'm proficient in the 2 stroke or four stroke area but I have good experience. Just so you'll know this is not my first p-51 as I had a four stroke 91 in the other one. Thanks

i wouldnt change it.....your p-51 will gain at least 10oz and have less power.....not a good combo. save the gas engine for another plane (big stick 60 maybe? it could handle the extra weight)

I wouldn't change it either but not for the reason stated above.....20 CC gasser will be heavier.....and is a little too much engine for a 60 sized airframe

depending on which one you have either the blue nose or the marie thats not the best gas engine for either one, you want a rear carb slim profile gas engine your going to be cutting the cowl up any way might as well keep the lines sleek, unless you don't care about the carb hanging out one side and the muffler the other.
the blue nose flys fine on a 120 4stroke try something like this, take a look at the 360 view http://www.troybuiltmodels.com/items/AEROVATE20R.html with about the same HP as a 1204st glow if your looking for a gas engine for the Mustang.
as for the Marie its a light frame for a gas engine mine flys great with a 91 surpass 4st way too much engine for that plane.

Did you already buy the Zinoah?? If you go into the gas engine forum you will find a lot of information about most all of the gas engines and be able to see what others using them have to say about them before you buy. If you do a search you may be able to find that engine being used in that plane and see what people think of the combo. I go gas after about the 1.20 four stroke. I still have a nice RCS 1.40 gasser with the rear carb. Love the engine but hate setting up the throttle linkage. These were very high performance engines, small like a glow but the power couldn't be compared, way more beans then a glow engine. RCS sold out and the engines are no longer made.
Gas engine forum is where you want to ask your questions about gas engines.}}}}}}