Charcoal Gas Bike

The project is to make a charcoal gas powered motorized bicycle similar to the few WW II era gasbikes I’ve seen on the web.

The engine here is a copy of a honda OHC clone, 37cc 4 stroke. Mounting kit from livefastmotors. It looked like a basic rear mounted chain drive kit which can also be adapted to recumbent bikes (as opposed to within frame kits)–I’ve built a couple of recumbent frames, too, and may use this on one. I’m hoping the kit is heavy duty enough as I am also planning to use it for support of the gasifier, filter, and cooler.

The gasifier itself is a slightly smaller version of Gary’s simple fire using a stainless steel stock pot and 1/2" nozzle. The test of this system appears on another thread here, easy gasifier for a log-splitter engine.

Below are pictures of the basic engine and drive setup as well as carburator and mixing modifications. The rest of the build will be coming over the next few months.

ok, i’m intrigued. looks like a great project to start out with. what’s the square metal can do?
my dad told me about a bicycle he saw in Tokyo (he was there when the peace treaty was signed at the end of WWII) that burned wood. i always wondered if that’s where the term “rice-burner” originated.

To give it a modern tweak you could go with a woodgas electric hybrid. You can get electric hubs with regenerative breaking and you could power both wheels. This would give you the freedom to mount your set up where ever you want. I think there are some very powerful light weight batteries specially made for this too.

Cool project!! Ill be watching :slight_smile:

Clap Clap Clap … You are tempting me … How much does that 4 stroke kit cost ?? I almost bought a 2 stroke in frame unit a month or so ago for $159. It was 80 CC if I recall right … Mike
Chinese of course …

Robin, the square can is meant to house an oiled foam air filter since I’m mixing charcoal gas and air before sending it into what had been the original air filter housing. I want to use the original throttle, plus I have the option then of making this a gasoline/woodgas hybrid, too. Interesting there were also versions of woodgas bikes in asia then. The ones I’ve seen pictures of were Swedish and Russian. The tech was really widespread I guess. I hear you about the electric bikes, Matt, but that seems way beyond me at this point. I was thinking this extended commuter bike might be fun to run on yard waste.


Hi Mike! I’m a great admirer of your projects. The four stroke is definitely steeper, but I just had to try running a bike on woodgas. This complete kit cost 365 at livefastmotors. Gearbox is not gears but a chain reduction. They’ve got the same engine sold alone for 165 and a 49 cc 4 stroke engine alone for 200. They are all Chinese copies of Honda engines. Be great to see a LaRosa version of a gasbike.



I wonder how a 2 stroke would do? I have an extra weed eater available.

Thanks Wayne,

2 stroke would need some way to introduce oil for lubrication. That was a technical challenge I avoided by going for a 4 stroke setup. The disadvantages of 4 stroke are numerous for this application, mostly weight/power output and cost. If you are thinking about 2 stroke engines there’s this project I found online. There’s an oil drip cup mounted on the gas/air mix carb input. It looks beautiful, not sure how it runs. I just don’t have the engine experience to know how well something like this would work.

Also Don M suggested about the above build that it looked like this two stroke has a compression release valve sitting on top of the cylinder, allowing it to suck gas mix into the lower part of the engine by pedal power and get things up to temperature in the gasifier so it is not working against the compression of the engine. Thanks Don for your expertise.

Cool Project!

Here are pics of my progress. The basic system layout is finished. Pretty much only need to work on seals before testing.


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TWLW ( traveling with less wood )

Thanks so much, Wayne, and thanks for this site! We’ll see what kind of mileage I can get per pound with this thing. I’m working my courage up to a bigger woodgas project one of these days.

Great Project
I’ve been wondering about oiling a 2stroke if running wood gas.
Some have oil injection but would the oil have to be diluted with gasoline?


Hi Gordon. Many thanks. My small engine knowledge is very limited, but I’m sure someone over at the small engine part of the forum would have an answer for you. I had seen a picture of a two-stroke project online that had an oil cup added to the carb but I couldn’t tell you if it was straight two-stroke oil or a gasoline/oil mix.

Here’s my understanding of how they did it.
Absolutely clean gas is a must. Usually a charcoal gasifier no soot, tar etc.
The basic is to feed the same amount of oil to the engine that would be mixed in the gasoline.
Take whatever ratio the engine uses 25, 50 to 1 etc.
Take a known measure of mixed fuel. quart or liter etc. (note the oil used)
Then run the engine at load til it is consumed.
Then you have the time that it takes to use the amount of oil you mixed earlier.
The drip will be timed to use the oil at the same rate

I wouldn’t bother with it unless, there were no 4 stroke options.

John, really nice to see ya updating the idea.
I would like to do this as well. Good way to use the slipped char from the truck.
All the best

very nice! thanks for the updates. looking forward to hearing about how well it operates.

Most 2 strokes run the fuel / air mix through the crankcase to lubricate the bearings and then port up the side of the piston(s). It is a rare 2 stroke that has reed valves or the such and takes it’s mix from the top and then injects oil for the crank or even have a sump for the crank. . From my experiences with woodgas and how the wood vinegar works on aluminum stuff I wouldn’t even think of running a 2 stroke. Just make sure everything stays above the piston and there are no issues that I can think of … ?? ML.

Looks awesome, nice work. Hope to hear soon how it runs.

Thanks, Chad. I should be able to start testing in the next couple of weeks. Fingers crossed.

I have been very interested in your bike since you started it,
Have you been able to test run your engine on the gasifier?