I have an old Ariens snow blower that has an 8hp Tecumseh engine. It's about 25 yrs old. I've kept it in good shape by keeping up on replacing parts as needed but it backfires a lot. Mostly when you are stopping it and it will put out a pretty loud bang at times. But it will do it also when starting but not as bad as when stopping. Once it it running it is mostly OK with a hiccup now and then. If I knew what was wrong I would do some work on it since it would be something to keep me busy during this virus problem. I'm retired and at home most of the time. Could someone offer up an idea on what might be causing this?