Whats the deal with the fire flame shooting out of my muffle

Dingo

LawnSite Member
Location
TN
Why does a flame shoot out of the pipe of my muffler when i shut it off. Its a new lazer Z? Is this something that will cause problems later? It also will backfire real loud sometimes. Is there something i should do to fix it?<br>thanks<br>Dingo<br>
 

Guido

LawnSite Silver Member
I'm no help at all when it comes to being a mechanic, but our Exmark 48&quot;'s with Kawi's do the same thing. (Big Bang and Fire show!) Our mechanic says, besides blowing apart the guts of the muffler, it won't do any harm. He told us piston and rings would do the trick, but ours are 10-15 years old. Yours, much newer, I wouldn't understand. Are your dealers any help or do they fit the description of &quot;the rest of them!!) Be carefull!!<br><p>----------<br>&quot;guido&quot;<br>David M. Famiglietti
 

Richard Martin

LawnSite Fanatic
Location
Greenville, NC
Just let the engine idle for a minute or so before shutting it off. When you drop RPMs from 3600 to idle a certain amount of unburned fuel will be in the muffler. If you shut the engine off without removing these unburned fuels the fuel continues to heat up until it ignites. It is also not the best thing in the world to shut the engine off without letting it cool down at idle anyway.
 

Getmow

LawnSite Senior Member
Location
VA
After letting it idle take it back to about half throttle then shut it off. That stoped it on my Kohlers.
 

John DiMartino

LawnSite Silver Member
Location
Walden,NY
Dingo-like the others here-I let my kohler idle for about 30 seconds to cool off the exhaust and valves before shutdown.The flame only happens when you shutdown and the throttle and rpms are about 1/2 and at least 2000rpms.As the engine spins to a stop,the mechanical governor tries to bring the rpms back up by opening the throttle,if the engine is spinning fast enough(wound up)at shutdown it will have time to draw a lot of fuel thru the engine,then it stalls.The muffler gets hotter immediately after shutdown,the fuel reaches flashpoint temp in the hot muffler and you have a flame.<p>----------<br>John D<br>
 
OP
D

Dingo

LawnSite Member
Location
TN
thanks for the responses guys. Im glad i noticed this problem because i use to have my gas cans a litte off the side. now that would have been a real fireworks show.<br>thanks <br> Dingo
 

Charles

Moderator, Friend, Angel
Location
South East
I put in mobile1 fully synthetic oil Kohler lazer after 135 hours of use. Didnt backfire at all in the first day of use with the new oil.hmmmm
 

Top