EDITION: Wilkes County
72 °
Registered Users, Log In Here
Lawn mower backfires and wont start ?


Posted 7:10 pm, 05/20/2010

Im glad you got that thar mower running


Posted 7:02 pm, 05/20/2010

What a concept ... glad ya got 'r goin' again.


Posted 6:59 pm, 05/20/2010

Wesman I'm glad you got it running. I know how aggravating a non running riding mower can be. Sorry I mis diagnosed the problem but at least you got some help from the others. Good Luck and stay cool.


Posted 6:53 pm, 05/20/2010

Everyone that posted about this riding lawn mower , thank you, I cleaned the air filter and changed the spark plug, And its running great, Again THANK YOU very nuch .


Posted 12:53 pm, 05/20/2010

I would just about gurantee its either water in the gas or a timing problem one


Posted 12:50 pm, 05/20/2010

If you leave your gas out in the sun and at night the gas can will expand in the sun and shrink in the night and cause water to form in the gas and your engine will back fire and want run.


Posted 12:48 pm, 05/20/2010

The flywheel key very seldom shears unless you are working the engine very hard or it was not tightened down properly.


Posted 12:43 pm, 05/20/2010

Check the valve adjustment, tight valves are usually the cause in addition to a bad spark plug. Nowdays there is alchol in the gas and that eliminates water problems in the gas unless it was left out in the rain... If you bump the starter and the engine bounces backwards it has sufficient compression (As specified by Briggs & Stratton), if it does not bounce back it is the valves. Most mowers today have OHV and it is very simple to adjust, this should be done every year to maximize performance and prevent problems... From what you described it sounds like a wet sparkplug.


Posted 12:31 pm, 05/20/2010

If all that Bigboystoys don't fix it, it sounds like the timing key steel thats in the end of the crankshaft under the magneto on top of the engine has sheered. If it has you will have to replace the key steel and mount the magneto back on the slot that lines up with crankshaft and magneto. It will be back in time and should run alright.


Posted 9:22 am, 05/20/2010

Backfires, more often than not but not always, are caused also be caused by an overly lean condition. Although my primary expertise is in automotive, Japanese 4 cyl. motorcycles and non computer controlled diesels, with small engines, their carbueration seems to be problematic very often.. Could be a blocked fuel tank outlet keeping sufficient gas from reaching the carb.

Check for fuel contamination in the gas tank ... droplets of water floating under that gas or clumps of anything down in the tank close to where the outlet hose attaches.

Since it backfires, that would probably eliminate a seat or blade cut-off switch.

To begin with, I would be certain that gas is reaching the carb by trying to by-pass the fuel tank, Do that by squirting a small amount of fuel directly into the carb throat. Does it have a priming bulb? If so use that but remove the airfilter and try to re-start it to be certain that the A/Filter is not obstructed and causing a RICH backfire.

Remove the air cleaner and try that. Like others have said, replace the plug.

Thats enough to start with ... if that doesn't fix it, report back to us with what you have tried and what you observed while trying.


Posted 8:47 am, 05/20/2010

Sounds like a bad cut off switch like the one under the the seat or the one where the blade engages.


Posted 5:57 am, 05/20/2010

ok, ill try that


Posted 11:57 pm, 05/19/2010

its the plug.


Posted 11:32 pm, 05/19/2010

see if the spark plug is fouled

Walking Stick

Posted 11:31 pm, 05/19/2010

Try changeing or cleaning the air filter.


Posted 11:06 pm, 05/19/2010

taps please


Posted 11:05 pm, 05/19/2010

its a troy bilt, the last time i used it , it ran fine, now backfires and just wont start /


Posted 10:45 pm, 05/19/2010

Air filter, oil filter, plugs, gas bunring too rich, shutting the lawn mower off before letting it idle down, exhaust back up.

Send me a pic and I'll diagnose. The lawnmower please, no personal pics allowed.


Posted 10:36 pm, 05/19/2010

I went out to start my riding lawn mower today, it started for a minute then backfired and stopped, so now i tryed to start it a just couple of times and the motor just turns over several times then backfires,

So what would cause this ? i check the oil before i mow each time and its good.

Advertise Here for only $1!
If you're seeing this ad, then so will your customers! Click here to create and manage your own ads, for only $1 a day!
Thrive!!! Energy, metal clarity, weight loss!!!
Thrive is a premium supplement that will provide you with energy, weight loss/management, mental clarity, lean muscle support, and much more! 3 simple steps daily. Create a free customer account today
Joines & James, Attorneys at Law
Joines & James, Attorneys at Law PLLC. 336 838-2701