I assembled one with an OS70FS 4-stroke. Mounted inverted with an OS 90-degree (in cowl) muffler extesion so that the muffler was on the underside of the fuselage. Thought it looked much better than the H9 orientation which is really set up for a 2-stroke engine. Definitely looks more scale. The engine runs fine inverted; no problem with siphoning, etc. Flew it both on wheels and floats; no problems with either. Sold it recently to a fellow club member who is enjoying the heck out of it like I did.

DKJ