Flames out of exhaust

Marks481 · Dec 9, 2016

You should be able to find a Kohler muffler that will almost be an exact replacement.... except reduce back pressure and not act as a heat trap. It will probably reduce the dieseling and back firing when you shut the engine off.

Also, if I were you, I would trim a big circle in the expanded mesh side where the exhaust exits to help get most of the heat out of the engine tub.

PT does a very stupid, poor job of designing and building mufflers.

MossRoad · Dec 9, 2016

The problem he's going to have with a factory muffler in that configuration is that the muffler sits between the engine and battery. There's not enough room to go forward, hit the battery. You can't go up, hit the hydraulic cooler. There's no where else to put the battery, as its over the hydraulic pumps. Maybe it could be turned 90 degrees and set to one side and a factory muffler could be placed longitudinally next to it. And, as I recall, the fuel tank is in the hood, above the battery and muffler area, but I could be mistaken.

Digger 258 · Dec 10, 2016

That's right, I think it's a 2003 model. It has all the pumps in the front of the motor, and the motor is in the rear of the tub. The battery is raised above the pumps and the fuel cell welded into the lid. I'll post pics in a bit. Wonder why they didn't use kohler exhaust?

Raw Dodge · Dec 10, 2016

Digger 258 said:
So I called Terry at PT and explained my glowing exhaust. He explained that the kohler motors heat up the exhaust until glowing, and most folks don't notice until they operate at night. He didn't seem concerned but just in case, he gave me a number to a Kohler Tech. The tech asked if just the headers were glowing or the whole exhaust. He said headers glowing is normal, but the whole exhaust muffler should not heat up that much. He suggested a number of things: 1) Exhaust manifold gaskets leaking air 2) Woodruff key on flywheel sheered, affecting timing 3) Fuel solenoid in carb not opening all the way 4) Carb set too lean (not adjustable) 5) Fuel pump not pumping enough. So I'm looking for manifold gaskets, with little luck, but I don't see anything that would indicate a leak. I pulled the fuel shut-off solenoid and touched it to 12v, and it is working fine. I cranked the motor with the fuel line disconnected and was rewarded with strong pulses of fuel - I replaced the fuel line for good measure. I don't suspect I can check the flywheel without pulling the motor though. Here are what my plugs look like - best I can tell they look like the "normal" picture when you google image "how to read a spark plug." <img src="http://www.tractorbynet.com/forums/attachment.php?attachmentid=491003"/><img src="http://www.tractorbynet.com/forums/attachment.php?attachmentid=491004"/> So I really don't have a plan moving forward, except trying to find new exhaust gaskets / studs / nuts. I am questioning if I even have an issue, or if the exhaust glowing at night is normal. I don't really want to find out by hosting a huge fire behind me as I'm pushing snow. Thoughts appreciated.

I have 5 Kohler commands right now as I type this,and all of them will glow parts of the entire muffler red at certain times,it is totally normal. Don't worry about it,these things are meant to run on the edge of too lean. There are many different applications and muffler packages,depending on if the muffler is in the path of the cooling air or not ,and the length of the headpipes has the biggest determination on whether the whole muffler glows or just the headpipes. I have 2 verticlal shaft command 25s ,the mufflers are not in the cooling air path at all,the headpipes make a 90 turn and thr muffler sits behind the engine with a large heat shield,these mufflers glow red on one end when mowing at dusk, again it's normal been doing it 16 years now with no ill effects other than you can't keep any heat paint on the muffler. I question a Kohler tech that didn't mention this variable ,and may not worth listening too,he's probably more of a pr guy for them. 3 of my kohlers will throw a steady flame out the exhaust when loaded hard,like blowing leaves on the steiner at dusk it looks like a propane torch tip out the exhaust and again this is normal.That engine was refreshed at 4500 hrs and is still going strong it never hurt it and it's how they were designed,yes i gutted the muffler so the flame is a little longer than usual but it's just fine .

Marks481 · Dec 10, 2016

The difference is that your Kohlers weren't mated to exhaust manifolds and mufflers built by Fred Flintsone, with openings that are half blocked by mis-cut holes, and absolutely no attempt to design anything that allows gas to smoothly enter the muffler.

Digger 258 · Dec 10, 2016

Thanks Raw Dodge for the perspective - I guess I'll just keep running her and hope I don't turn into a big road flare! The motor is making good power and running smooth so I suppose that is indeed how it's supposed to go. As for the Fred Flinstone Muffler, it sure looks like the last bit planned as they were fitting it all in the tub, and I am not sure it "muffles" anything, the PT is loud as all get out.

Thanks again, I'll let you know if anything changes.

MossRoad · Dec 11, 2016

I've got a Kohler factory exhaust system and I've never seen it glow or shoot flames out the rear. I'll have to look better.

I think they didn't put a Kohler exhaust on yours because it won't fit in that configuration.

joshlee · Dec 11, 2016

Thats interesting to hear that about the Kohler mufflers. Thanks for your info on that.

Raw Dodge said:
I have 5 Kohler commands right now as I type this,and all of them will glow parts of the entire muffler red at certain times,it is totally normal. Don't worry about it,these things are meant to run on the edge of too lean. There are many different applications and muffler packages,depending on if the muffler is in the path of the cooling air or not ,and the length of the headpipes has the biggest determination on whether the whole muffler glows or just the headpipes. I have 2 verticlal shaft command 25s ,the mufflers are not in the cooling air path at all,the headpipes make a 90 turn and thr muffler sits behind the engine with a large heat shield,these mufflers glow red on one end when mowing at dusk, again it's normal been doing it 16 years now with no ill effects other than you can't keep any heat paint on the muffler. I question a Kohler tech that didn't mention this variable ,and may not worth listening too,he's probably more of a pr guy for them. 3 of my kohlers will throw a steady flame out the exhaust when loaded hard,like blowing leaves on the steiner at dusk it looks like a propane torch tip out the exhaust and again this is normal.That engine was refreshed at 4500 hrs and is still going strong it never hurt it and it's how they were designed,yes i gutted the muffler so the flame is a little longer than usual but it's just fine .

alman · Jun 20, 2017

Digger 258 said:
After a long search for the right carburetor rebuild kit (I have the Kohler CH730), I decided to rebuild the crab. I went with tmarks's thought that it was running too lean, causing flames at idle. Put the carburetor back in, and she fired up fine, and seemed to run smoother. I was really excited. A few days later (today) I did about 45 minutes of light fork work. When I pulled the PT into the barn to park, I opened the hood to turn off the fuel cut off while running, so I can park with a dry float. What did I see? The entire exhaust was glowing red. I moved the throttle from idle to full, and a long blue flame shot out for a second. Glowing exhaust has me a little nervous. Is this normal, and I never noticed it before? Or do I have a problem? As far as I can tell, the coils are working fine. I'll post a pic of the spark plugs next chance I can get to the PT. Thanks for your input - I love the PT and don't really want to burn her to the ground (nor my barn).

Hi
From Calgary, an have a KOHLER LH 755S engine, , an serious heat issue, , ,

exhaust pipes heat up cherry REAL quick, , when issue first started, lost serious power, an leane dover an saw flames coming out the muffler, , NOT GOOD !!

shut is down, re tried to do run 15 mins later an b 3 long, same issue loss of power an flames out !

anyway, for more info an pics please go here, ,
Firstly, my apologies for posting in another site an copying here,, jus wanna get this problem started out, , , its off a post hole digger an thats all I've got for an income, , , was working Oil an Gas in Alberta then the **** hit the fan, , ,

money, what money is very tight so need to try an resolve this as far as I can with a little help from the "net !

Hi All
I have a KOHLER 755 engine with a real ugly problem

exhaust ports get cherry after about 10 mins of use,
figured exhaust system was an issue, so rebuilt it with expertise of Wayne Drewoth, ,

ran it for 10 mins at half throttle an engine ports went cherry !

open to suggestions an the like, , , am mechanically inclined but never really work on engines like this before
pulled flywheel, key ok, spark an magneto cleaned off an ok
pick ups re set to spec,
no change in operation, , , goes cherry.

230 hrs on engine