Carbon monoxide doesn't burn. The wood gas was produced in a similar way to 'town gas' was produced by burning coal in an oxygen-free atmosphere. Wood is similarly burned in an oxygen-starved environment and the result is hydrogen gas as well as CO - basically the 'vapour' from the heated (but not strictly-speaking burned) wood is used to power the engines concerned. The device looked like a pair of dustbins mounted on the front of tractors. This was done during WW2 when petrol was unavailable and the techniques is actually still applicable and on 'standby' in the USA for use during times of war.During World War II, carbon monoxide was used to keep motor vehicles running in parts of the world where gasoline was scarce. External charcoal or wood burners were fitted, and the carbon monoxide produced by gasification was piped to a carburetor. The carbon monoxide produced by this process is known as wood gas.
This doesn't distraact from the fact that CO is a by-product and highly dangerous.
You can find more details on wood gas powered engines here.
http://www.woodgas.net/files/FEMA%20eme ... ssifer.pdf
What is interesting to note is that about 20lbs of wood produced the equivalent of 1 gallon of petrol
.