Hello,
This has happened twice now on my old Wal-mart Yard Machine... I completely mow my yard.. turn off and a small fire starts coming out of the exhaust pipe..
At first I thought maybe old grass was in the cover or muffler , ( The cover with all the holes in it attached to a 3/4" or so, exhaust pipe)... It is all rusted out.. I looked again and the flame is definitely coming from the 3/4" pipe.. No Grass... So I'm guessing it is a build up of gas that can't burn because of the exhaust shooting out carbonioxide with little oxygen to fuel the flame.. Plus the air compression.. But that is just a guess..
What can I do to repair this and keep these fires from happening..?
I had a similar problem with my 1986 craftsman lawn tractor. It backfired so much (there were flames comming out the muffler) that the muffler glowed red, then the muffler screws got melty and rattled out and the muffler just fell off. Now I just run the mower without the muffler because I don't feel like putting a new shear key in it (It has a timing problem).
So if that sounds like what may be happening with your mower, then its a timing problem and you need a new shear key.
Yea, I don't notice it back-firing.. It has back-fired before, but it runs ok I think.. It just catches on Fire..Ha... Flames right out of the exhaust...
If it's an OHV engine check that your pushrods aren't bent at all, and make sure the valves are opening and closing correctly.
#6
SONOFADOCKER
The carb has an anti back fire solenoid on it . Stops fuel when you shut off the machine . Yours is deliver fuel & fuel is igniting when the exhaust valve is open . Fuel ignites due to normal heat . Try throttle down before turning it off .
The carb has an anti back fire solenoid on it . Stops fuel when you shut off the machine . Yours is deliver fuel & fuel is igniting when the exhaust valve is open . Fuel ignites due to normal heat . Try throttle down before turning it off .
Yep my manual says idle for 15 to 20 seconds before shutting off if i dont mine backfires loud..
#8
rmancini
I've noticed that as the Ethanol content in gasoline increased, a lot of my equipment started to run "funny" and some backfired and dieseled. I tried the middle grade of gas (instead of regular) and I haven't had any problems since. I'm thinking that carbon deposits on older equipment may heat-up and glow causing the cylinder(s) to fire when the exhaust valve is open. The higher Octane gas seems to prevent this.
It's for sure a little more expensive to use better gas, but, but I'd rather not take the chance of damaging my goodies.
Rich
