Birggs 16HP OHV Backfires at high speed

djggarage · #1 Oct 21, 2009, 11:23 AM

Just got a used Craftsman riding mower with a 16HP Briggs& Stratton OHV engine, model #310707. Originally it would not start, click or do anything at all. I did a lot of cleaning on all the switches, charged up the battery and it cranked with an initial loud backfire. Started it again and it ran fairly good but had an ocasional backfire. Did a basic tune-up, ie. new plug, air filter, oil change, valve adjustment (set at .004) and took off the electronic gas valve solonoid and draineed gas out of carb. Gas looked clean, no junk or water in it. Gas in the tank is new. Engine starts right up , but still runs with the ocasional backfire at full throttle. It does have a range of running speeds and at idle it seems to run fine but I can see the governer is still surging a little. Also when you go directly from full throttle to slow idle, it always gives a louder backfire. The fuel mixture adjustment does not have much if any effect and it has a limiter on it. Any suggestions on what to do next to get rid of the backfire?

djggarage · Oct 22, 2009, 06:50 AM

Clarke.
Thanks for the suggestions. I will look into this further this evening. The muffler is very loud ,like it is burned out.

LP Lawnmower rc · Nov 6, 2009, 09:37 AM

I also agree it seems like the muffler needs to be replaced and if the backfireing contunius try replacing the piston rings because the addition of oil to the great amound of gass being put into the cylender may cause a large backfire... please excuse my spelling i have a slight problem with it



At Ask Me Help Desk you can ask questions in any topic and have them answered for free by our experts. To ask questions or participate in answering them you must register for a free account. By registering you will be able to: Get free answers from experts in any of our 300+ topics. Accept money for answers that you provide. Communicate privately with other members (PM). See fewer ads. Sign Up!