Tried new shut off procedure

[diesel_nut]

1) Turn throttle to idle for 30-60 secs (longer the hotter the engine is).
2) Turn key off AND push throttle up to ~ 3/4 at same time.

The key here is the engine rpms were low to start with (at idle).

It shut down very quickly and no hint of backfire.

I think I like this better than shutting it down while running at 3/4 throttle. Something about throwing all that unspent fuel into a high rpm spinning engine I don't like.


Give it a try. You might like it. Might not.

 

[Bob_Bainbridge]

Sounds good if it works. I'll have to try it next time. Supposedly when you turn off the key the fuel shutoff solenoid prevents feeding raw gas into the engine. I know there's still gas in the carb bowl but maybe with the inlet closed it doesn't feed the engine.

Bob B.

 

[joelaudi]

That what I have be doing since I got my 5252. I think that when the engine is turned off with the throttle is at idle, the fuel is pulled from the idle circuit in the carb and causes the backfire. With the throttle is pushed to full, there is no fuel to ignite. Just my thoughts.

 

[Willl]

Does the little 'pop' you get shutting down the 'other' way bother you that much ?

The reason I asked is my rider does this ever time at shut down.

I learned to live with it. I can't see that it's doing any harm.

 

[diesel_nut]

Sometimes it's more than a pop or a poof. It's a VERY loud bang.

 

[joelaudi]

I think that the backfires are not good and causes harm. My muffler developed a crack that I believe was caused by the loud bangs. Anytime that there is a backfire it can't be good.

 

[savageactor7]

My dad was death on any equipment that backfired...he said it's the same thing as a mine explosion and something to be avoided at all costs.

Truthfully I dunno but I still follow that advice.

 

[Bob_Bainbridge]

Does the little 'pop' you get shutting down the 'other' way bother you that much ?

The reason I asked is my rider does this ever time at shut down.

I learned to live with it. I can't see that it's doing any harm.

I always got more than a little "pop", with both a 1450 and a 3235. It;s loud enough that all the neighbors turn and look. I tried turning the key off and shoving the throttle open at the same time today and it seemed to work.

Bob B.

 

[diesel_nut]

From what 'they' always told me, backfires can unseat piston rings and even break them.

 

[OhioGuy]

I gotta try that, I hate that backfire, I'm waiting for the muffler to split open!

Thanks,
Curt

 

[JSharp]

The backfire is a bad deal and should be avoided. As we've talked about in other threads, I don't understand what the problem is. Just leave the engine at 2/3 - full throttle and cut the ignition. Problem solved.

I'm not sure why so many people keep trying to do it differently when that technique is known to work and is recommended by the factory. I certainly don't see what harm can be done by it.

 

[diesel_nut]

You are, of course correct. But many of us were brought up to never shut off an engine with it revving high. Just bothers us to do so.
No big deal either way.

 

[Bird]

You are, of course correct. But many of us were brought up to never shut off an engine with it revving high. Just bothers us to do so.
No big deal either way.

Yep, it took me awhile to get used to turning a key off with the throttle wide open, but that's the way the manual said to do it and it sure beat having that big explosion by turning it off at idle.

 

[JSharp]

I understand the point guys. I was taught to never shut an engine off at wide open throttle too. But, it works in this case and it's clear why that is. It's a function of the electric fuel shutoff arraignment.

 

[The Dougster]

Backfires are an indication of a mechanical problem, but you already knew that didn't ya? Check the timing and probably valves... should be a relatively easy fix...

 

[jimdiesel1]

Doug,

What happens is actually not backfiring, it is afterfire, raw gas being breathed into the hot muffler at shutdown and igniting. Not a bad valve issue, it is remedied with using the proper shutdown procedure, 2/3 or higher throttle position and turn off the key= no afterfire. Explained earlier in this thread.

 

[Rainbow6]

On my 2518 I pull the throttle down low, then pull the choke as I turn off the key. Works for me, no backfire.

 

[turbojerk]

I usually let my Cub idle for a few minutes after a good mow and take that time to blow out the engine cooling fan while its rotationg and then shut it down.

So far I haven't had a backfire in 3 years using this method.

 

[vtr996]

I'm running an '08 1045, Koehler 20hp. This thing after-fires no matter what I do: idle it down for 3minutes, run it up to 1/2, 2/3, full, doesn't matter.....BAM!! Someone here mentioned cutting it off with the choke, works like a charm! Down to idle, full choke, kill ignition as it dies.

 

[Bob_Bainbridge]

Backfires are an indication of a mechanical problem, but you already knew that didn't ya? Check the timing and probably valves... should be a relatively easy fix...

In this case it's more a Kohler engineering problem. Just about every mower made with the Kohler engine does this. The 1450 required idling before shutoff and the newer ones require high throttle position before shutoff. If we had to do that with our cars I'm sure there would be a quick recall.

Bob B.