I have used my M67 something like 150 times since I bought it new 2 years ago.
This morning (lord knows why I did this) I decided to light it with no oil in the drum. My idea was to light it and have it on minimum heat, something like 1 drop of fuel every 2 seconds, while I filled the tank with oil.
I lit it and turned the fuel down to the 1 drop/2 seconds. After 2 mins when I was ready to pour the first cubie of oil in I noticed flames in the exhaust. I switched off the fuel (still dripping slowly) and lifted off the tank, expecting the thing to calm down. It got hotter and hotter, the exhaust was glowing red and flames were coming out of the top. I had to keep dousing the outside of the drum with water to try and keep the temperature down. This lasted for about 30 mins. I was in a bit of a state.
Is it possible that lighting it when it was in air (even on minimal fuel) could have resulted in a much hotter burn and the 30 min burn was getting rid of the residual crap and gunk built up inside the doughnut from using it for 2 years.
I have always been aware that a small leak in the doughnut could cause a similar problem, leaking oil into the combustion chamber. However in this case the heater had been left dry so this couldn't be the problem.
Has anyone experianced this before.
