Bicycle engine gasser


Active member
No idea if this will work,but something struck me today: when I first got interested in RC planes,late 1980s, they were mostly nitro engines, and the cox .049 was the most common as they could be bought new for about 40-50$. Technology has progressed a lot since then, brushless engines can be had for $10 for the mass produced inexpensive end of the spectrum and gassers are less common. OS has replaced COX as the most common brand,built with far tighter tolerances, more reliable and more powerful,but almost 5x the price of the lowly COX.049. until a few years ago I was adding cheap Chinese 2 stroke engines to bicycles,sometimes called the HT engine after one of the common brand names (Happy Time) I wonder if one of these dirty,heavy, unreliable cast potted aluminum and steel power plants on a large enough airframe with sufficient glide, enormous wing,and cartoonish propeller with extreme pitch could power an aircraft? They weigh about 10# plus gas! They produce a bit over a horsepower at 5000 rpm and go up to about 13000, properly tuned can be 7 hp,they make 49 & 66cc models,as in US anything 50cc & above is no longer an assisted bicycle but a powered cycle or moped and must be license that insured. Using the same block they port the 49cc and boring it out and adding a larger piston they sell them as 66cc (commonly called 80cc but that's inaccurate) and these things are so randomly assembled implants with no quality control they often leave bits of casting burrs all over the engine which you have to file off, the 66cc is seldom any more powerful than the 49. The 49 revs higher and I've noticed sometimes better acceleration on the smaller one. The 6- is a bit lighter though. I wonder if anyone has been able to make this work? I searched and didn't see anything but maybe there's some dark corner I missed. Wholesale these engines can be had for about $47, and that's including a crappy cdi meant for a 4 stroke,a leaky unreliable carburetor and everything you need to attach it to a bicycle including a leaky teardrop gas tank


Techno Nut
Most peeps are headed down the E-BIKE road these days. Peter Sripol did a solar/ E conversion recently. Think I would have picked a more efficient power transfer method than he did, but was good and entertaining!

I've thought about strapping an EDF or two on one of my road bikes for giggles too.



Wake up! Time to fly!
Problem with nitro motors is fuel consumption not really viable as a "transportation" method. You could assist by using gear boxes but still very inefficient AND super expensive ($30 + per gallon) means to an already solved end.