I had been cutting my hay for about 45 min. when I smelled something burning. When I stopped the tractor I could see smoke start to rise from under the hood. Thankfully I had my fire extinguisher and was able to put it out quick. A bird had built a nest around the exaust manifold. The only thing it seems to of damaged was a hose leading from the engine to the exaust pipe. When I took the hose off there was oil inside the hose. What is this hose for? I'm not that great w/ engines so if anyone has any ideas please post them.