Archive through October 11, 2016

[jwiggins]

Rob F, Concerning the backfire You mention "about the same location every time",,,,, is this near a hill or incline possibly???

Or as Earl Mentioned is this "same location" in relationship to your cut pattern and how long tractor has been running???

Also to clarify this backfire is at WOT correct???

 

[hydroharry]

Rob F - another possibility is your muffler itself. You mention you're surprised it doesn't split the muffler. It may just do that one of these times, or blow the back end off, which is more common.

How old is your muffler?

It's my understanding the carbon builds up inside the muffler and acts almost like a sponge to the rich fuel fumes from these Kohlers. Usually you hear about "bangs" when shutting the engine off - which is often from this fuel build up in the carbon and the temp of the muffler being hot enough to ignite the fuel. I suspect it could happen when you're driving/using the tractor and especially if you get to some un-level point that may direct the muffler slightly different.

If you don't find anything based on what Earl and Jason mention then it could be time for a new muffler (or at least remove it and shake as much crap out as you can - if something comes out all the better).

 

[digger]

OR!
Idle it down after using it for 15 or 20 seconds, and THEN shut it off.

If it still does it, THEN go for the decarbon of the head and or exhaust valve and on and on and on.

 

[jwiggins]

Charlie, I can "Faithfully" initiate backfire every single time w/out the "idle down before shutdown"

 

[hydroharry]

Jason - you better get religion then and de-carbon your head and piston. If you don't the carbon build-up will eventually cause your engine to fail (either by a chunk of carbon breaking off and scoring the cylinder or chip/gouge the top of the piston). Kohler states to do it every 500 hours and your K321A certainly has more than 500 hours and who knows the last time or if it has ever been de-carboned.

If by the odd chance your head and piston are actually fairly clean then your "BANG" is likely due to the muffler.

 

[aewald]

Charile -
Thanks for the fast shipping and the peanuts!

For Everyone else -
I'm wiring my amp meter, which side is pos and neg?

 

[digger]

Austin E.
Isn't your amp meter marked POS+ and NEG-?

 

[aewald]

Charile -
I don't think so, unless its hiding between this paper that is redish, its a IH Amp meter with part markings on it.
And if this off topic let me know, Can I connect the B+ wire from the Stator on the engine to the amp meter? Or is there a better way to get the energy from to stator back to the engine?

 

[digger]

If your talking about your 149 with 20HP Command, yep, it's way Off Topic, and would probably be best in the Cool IH Cub Cadets Not OEM but better'n' new ! ! ! section.
That way you could start your own thread and keep it separate in case someone else does something along those lines.

 

[wshytle]

Rob-

All that has been mentioned is good but no one mentioned timing. If you de-carbon the head and time it close the problem should go away. Also, using high test fuel helps with the carbon issues IMHO.

.

 

[rfuller]

Lots of questions.... I mow wide open really no load, about 20 min into mowing the same pattern. On a level surface. I use premium gas with sea foam. I do idle down when I head back to the garage usually for a few miniutes. No back fire after turning key off. when the bang happens i don't think the engine skips a beat. I'll pay more attention next time. I'm leaning toward the muffler. how do you de-carb the muffler? Don't know how old the muffler is but looks pretty rusty and holds together.Thanks.

 

[dschwandt]

If Ya keep banging away like that, you might just blow the welsh plug out the front of the engine.
Had that happen to one of mine once. Talk about an instant oil spill!!

 

[dschwandt]

So, a friend came by yesterday and wanted to know why his 1200 wanted to "run away"

I told him he needed to elect a new governor, among other things!
Ya think maybe!!

 

[nbextermueller]

Goodness! Even took out the rod dipper! How did it not seize up...

 

[dschwandt]

Yes, and it appears to be a fairly recent O/H by the looks of the piston &head. Really clean but no marks as to what size overbore if any.
Will find out soon, as I'm headed to the machine shop now.
This rig is a veteran of the Stertz plow day a year ago!

 

[eford]

That doesn't bode well for my 1200's engine. I haven't opened it up yet. My governor shaft fell out of bushing on engine.

 

[wcompton]

Guessing: re-used governor stub shaft that the governor runs on (and probably governor gear). If the piston is as clean as listed, and if the governor rod is as discolored as it is, that would be my contention.

Ironically these are not included in many of the online-sold kits.

Possibly the second most common failure behind the grenade gears.

 

[dschwandt]

Stub shaft in block looks good and the thrust washer was still on it.
What caused the failure I believe was the broken tab on the governor shaft.

 

[dmerkle]

Kohler backfire
My 149 had abad backfiring on a stock muffler. I start using Marvel Mystery Oil and turned in the high speed adjustment on the carb a 1/4 to a 1/2 turn. Backfire quit. Watch the spark plug so you don't lean carb too much.

 

[eford]

Rob F. Just try removing and banging all the crap out. Harry is, oh boy, correct.
Other than opening it up and cleaning and welding back together not much you can do.