US engine
 

I am getting a US engine 41cc new in the box for $100. Are they a good engine? Where are they made and do they have a website? To be honest I've never heard of this brand of engine.

I don't think they are in production any more. They were really more of a thing about 20 years ago. That shouldn't be too much of a down side as it probably uses a Walbro or Zama carburetor, the parts for which are probably still available. It isn't going to be a 3-D engine but would be good for things like WWI planes or other short nosed aircraft that are going to need nose weight anyway. As a magneto engine it is going to be heavier than the latest round of hot 40 cc engines with electronic ignition. You may be able to get some accessories from B&B Specialties. it will probably take about an hour of run time to really break in. I'd stick to 32:1 for the fuel oil mix.

Had one in a Giant Aeromaster (kit built, heavier than ARF) and it flew great. No 3D stuff (plane weighed 20 lbs) but plenty of power for giant loops. Engine ran very well and dependable, never a dead stick. Plane met it's demise due to dumb thumbs. Would recommend getting a spring starter.

John

Had one in a Giant Aeromaster (kit built, heavier than ARF) and it flew great. No 3D stuff (plane weighed 20 lbs) but plenty of power for giant loops. Engine ran very well and dependable, never a dead stick. Plane met it's demise due to dumb thumbs. Would recommend getting a spring starter.

John

I have had several over the years. They started out as Quadra Engines, made in Canada, then bought by U.S. Engines in New York I believe and the name was changed from Quadra to US engines. Although Quadra made several sizes of engines, all magneto powered, U.S. Engines only got involved with the 25cc (basically a Homelite 25cc string trimmer engine converted to RC use) the 35cc and 40/42cc which U.S. Engines marketed as their 41cc.

The 41 is a nice engine, easy starting and extremely durable. Unless you deliberately try to damage it, the engine will outlast you. The 25 is a side exhaust and the 35-40/41/42 are rear exhaust. To tell the 35 from the 40/42, when looking at the rear of the engine, there are four bolts that usually attach the cup/motor mount. On the 35cc engine, the top two bolts are spaced closer together than the bottom two. On the 40/41/42 engines, the four bolts are all equally spaced.

I have attached a copy of the Quadra Engine Operation Manual covering from the 35cc, 42cc. 52cc and 100cc Quadra engines.

Thanks for the helpful info! I have another question with regards to the prop bolt. In the center of the prop bolt is a threaded hole, for what i think is for a spinner bolt, but it is too small for the spinner bolt that typically fit a DLE 35. Is there another prop bolt with the appropriate center diameter that would fit a US 41cc?