Idle down or boom
 

My uncle had explained to me that our older kohler engines need to be idled down before run down or run the risk of backfire. Anyone tips to prevent this or is this just the nature of the beast?

I always idle all my cubs to prevent backfire, 30 seconds is plenty.

I've always idled mine down too. Even with an idle down Dad's 125 used to backfire after shutting off. We got used to shutting it off and immediately covering our ears. Even on my 147 sometimes I still do it.

ALL engines should be idled down for a while after running. Just like you don't like to just collapse at the end of a hard run, your motor doesn't like to be shut down without a cool down. I even let my vehicles idle for a little while if they have been running hard. (Like when I'm pulling a trailer, or they have been on the interstate running hard.)

The backfire is a result of fuel entering a muffler that is hot enough to ignite it. Sometimes it is indicative of an engine that needs some attention. Too rich of a fuel mixture. Or even too lean, causing excessive heat. Lots of reasons. Most of the time it can be fixed, but just letting them idle may be all they need.

If yours doesn't backfire, great!! But you should still be in the habit of letting it cool down. Your uncle is correct. Sometimes, the simple answer is just hat. LET THEM COOL! :beerchug:

FWIW, this topic gets beat to death on here every few months.

I always idle mine for a while and don't have a problem, but my dad forgets to once in a while since my cubs have the only older Kohlers he's used. If we're lucky, someone is walking by on the street and it scares the crap out of them. :biggrin2:

I don't know if there is a difference because of the different mufflers, but my narrow frames seem to backfire and the quietlines don't. Of coarse, my mag 20 likes to backfire once in while when I re-start it right after being shut off.

With mine I always ill it for a few seconds at minimum just to let em ease into it. But more times then not I just the fuel off and let the carb run out at idle . Just a old h abbit from my quad days

ive very rarely had backfire on my cubs, I did start my 102 in the garage the other day and with the door open man it sounded just like a cannon shot. I bet people enjoyed that :biggrin2:. I always idle my 102 down for a minute or so then take it and either wash it or use an air hose and blow it all down. I remember my father doing it with his 123 and now that's what I do. is it me or are the old ones a lot easier to clean because they don't have as many shields, I cant remember blowing the engine out on my 682 cause it sucked to get to haha.

Same here

:Cub2:

Even when I do idle it down, I still always stand there w/hands in the air and holler "I give up.....Don't shoot".......................

Sadly though, it don't always work!!!!

Somewhere I read in a manual, when shutting off the kohlers with compression releases, to always turn the key off and go to full throttle. Since I've done that I've never had a backfire. My son was riding it and didn't do that it it backfired and I laughed as he jumped. So turn the key off and push to full throttle and no backfire, works for me on my 149.

hahhaha that's a good one . i was looking at a 129 awhile back that backfired .

If the engine is slightly warm on my 2284, I get an explosion at idle if the ignition is turned off.

But, at above half throttle, the explosion never occurs,,, :bigthink:

I think that is explained in some manual. :bigthink:

Backfire
 

If the timing is spot on and the carb is adjusted properly the engine should not back fire with just 5 seconds of idle. My Dad's 127 never backfired until the carb was rebuilt and it would have to idle for over 30 seconds. I pulled the carb, reset the float (was just a tad off before) and it has not backfired since. I also adjust mixture screws for summer and winter operation, need less fuel in warm weather.

Jim

try holding the throttle pedal on your car tight to the floor and key it off.
new L&G engines would backfire but due to customer complaints we have the anti back fire valve

"try holding the throttle pedal on your car tight to the floor and key it off. "

Is this car fuel injected or a carb? Do I hold to the floor until full RPM or ?????

Jim

carb. hold till the valves float

That reminds me of a story my brother told me about dad's 125 with the backfiring issue....

I (had) a very proper grandmother, my mom's mom. She came over to visit one time when my brother was mowing with the 125. She was getting out of the car, walking towards the door, and he shut the engine off. Idled it down, it shut off and BLAM about gave my grandma a heart attack. It makes me laugh just thinking about it.

I always idle down, and shut off the fuel. I did have fun once when I suddenly lost spark while mowing at wot and the engine quit. My wife dropped dishes in the house it was so loud!

Speaking of backfires, I named my old 78 ramcharger "pops" because after I restored it, it backfired out the dual pipes every time it shut down, flames and everything! Scared my co-workers until I got it sorted out.

There's the key!!! It had an issue and you fixed it!!!
You found out the issue, repaired it and the backfire stopped didn't it. :beerchug:

Sure did! Idle speed was set too high and it was running too rich. Made the adjustments, problem solved!

Not as easy as adjusting a cub, but same basic principles.

I quick little re-seating of the exhaust valve, and no other adjustments to anything has always made the backfire go away for me.
For 100 hours or so anyways.