Had a 535A MFWD Challenger (MF 100 hp) that in just a matter of a day birds had built up corn and grass debris around the turbocharger. Drove the tractor to the field and started patching some terraces with a 3.5 yard dump pan - gives a heavy load filling, then not so heavy hauling then light load going empty then do it all over again. I had only been working fifteen minutes or so and got out of the cab to check something. I smelled just a slight smoke smell as I got back in the cab - thought nothing about it, figured someone was burning a pasture upwind. Stuck the scraper pan in the ground and about ten seconds later seen a puff of smoke comeout from under the hood. Jumped out to see smoke and hear crackling sounds around the turbo. Tried to get the panels off the side of the tractor and couldnt because I could not turn the knobs with myfingers - all the while the crackling sound getting louder and faster rapidly. I knew if I could get the panels off could probably get it out easily by throwing loose dirt on the fire - have done that before on other stuff - but I couldn't get the panels off! By this time I was in panic and wasn't thinking very straight - I basically gave up. Figured as soon as the fire got the fuel line that ran up in that area it was all over with. got my radio and cell phone out of the cab and took the tool box off...... tool box!!!! Heck theres tools in there. Got an adjustable wrench and turned the latches and got one side panel off -wind blew in there and flames shot out - big fire quick. But as luck would have it an air conditioner hose melted before the fuel line and when it blew it blew the fire out. I threw some dirt on the engine as there were still glowing embers and was about to re-ignite.

I was able to go ahead and use the tractor till Cat had a chance to come out and repair the air conditioner - with the windows open. It melted some wire loom and a little wire insulation but not enough to ruin the wiring harness. The AC hose was all we replaced.

My point is I went from a state of alarm, to a state of panic where I was not thinking very well, to a calm state of acceptance (this sucker is going to burn, hope my insurance is good, and in that state of calm could actually think of something constructive to do. I'd almost bet that combine was not set on purpose. Catch a little chaff soakes with fuel then catch the plastic and fuel on fire and see how fast fire progressed. If a fuel line happened to have broken and sprayed atomized fuel on something hot it is basically a blow torch. Put a blow torch on a plastic combine and plastic fuel tank and see how long it takes to have a big fire and not much you can do about it.

John