Backfires

[fcurrier]

Mouse Milk:
http://www.flightsystems.com/p-61-861S-MM.html
Similar to Charlie's Snake Oil, maybe?

 

[digger]

I've used Mouse Milk for years.
Here's a place to buy it cheaper.
http://tinyurl.com/pdqwvej

 

[mfrade]

Sounds like the stuff JC Whitney used to sell.. "Rebuild in a Can"..

First it says it's a penetrating fluid then it says it'll eliminate friction.. I guess it can dry wet wires also..

 

[digger]

Yep!
Most of the time, NOTHING works except what the guy saying it doesn't work uses!

 

[mfrade]

I'll agree with that one Charlie!

 

[bjamison]

FWIW, this backfiring is a timely topic. I've never had trouble with my cast iron Kohler engines back-firing, but if you have one of today's newer engines, especially a Kohler Command, backfiring the engine can be trouble. Sometimes when they backfire, they can blow out the head gasket. I think Kohler recommends not idling down below half throttle when shutting down the engine.

 

[kide]

Uhhhh, replying to a 2008 post is timely?

. Not sure if Bruce ever got the cure, but he hasn't logged on since November 29, 2012 ..

 

[jdiederichs]

Yes, the old post was a surprise, now to refresh everyone's memory one last time: The carburetor on todays engine has a shutoff solenoid. It closes when the key is switched to the "off" position. It functions by closing the main jet, or high speed jet.

That, and that alone is the reason the manufacturers advise shutting off with the throttle above 1/2 throttle. With the carb butterfly open (at 1/2 or better throttle position) there is no vacuum to draw fuel thru the idle jet, and none can get past the fuel solenoid closing the main jet= no backfire.

Simple huh? it has been the most difficult thing to teach operators! Especially those with older engines, who always shut down at idle and are hard to change.

 

[kide]

Jim - new engines spoil the tradition between my neighbor and I.... I shut down the 129, it lets loose with a KABLAAMM worthy of a magnum 12 gauge, and he shouts "PULL !" from his garage, 300 feet away ....

 

[digger]

 

[drglinski]

Dad's 125 used to backfire all the time when it would be shut off. You'd idle it down and let it run for a bit to "cool off" then turn the key..as soon as it quit turning over a BLAM would ensue. Us kids just got used to shutting the key off and then promptly plugging our ears. Sometimes I still do it out of habit while on my 147. I think idling it down does help.

 

[kide]

Hot muffler + rich mixture unburned in combustion chamber + air coming back into muffler from outlet... when the air/fuel mixture reaches the perfect ratio we have

. Amazing thing is, my 129's been doing it since 1985, since mid '90s on the crate motor, without blowing the ends out of the muffler.....