Woodmizer LT 15 dies when I lean the mixture

flyingparks · December 28, 2021, 08:35:52 AM

Greetings All,

I was doing some holiday milling and things were going great. Then I shut the engine down after milling a nice log. I refilled the tank with some new ethanol-free gas, the same stuff that was in there already in the tank. The mill had trouble starting. I waited and enriched the mixture, basically choke full on. Then it started up just fine. But it cuts off when I lean the mixture. It won't run at all if I lean the mixture, but sounds pretty good with the choke fully on. Any ideas? My first thought is a sensor issue of some sort. It has been running just fine for a year or so. Kohler G18 engine. Altitude: 7,000 ft. Temp: just above freezing. Any ideas are greatly appreciated. The lady is excited for her she shed.

Southside · December 28, 2021, 08:51:21 AM

Sounds like a fuel obstruction. Maybe filling the tank jossled some junk around and it got sucked into the pickup tube. I would try a fresh fuel filter and see if you have good flow coming out of the fuel lines, if not clean them out or replace them.

kantuckid · December 28, 2021, 08:53:34 AM

Which engine? My older (maybe 21 years?) LT15, original Kohler Command Pro 15 hp, now has a Chinese clone carb, the 2nd fuel pump, the 2nd gasoline fuel shutoff, the 2nd solenoid and a Chinese tach/hour meter that never worked. Mines at maybe 1,250' elev.
The carb I've got was cheap and since the OE carb is NLA- it's what I deal with but honestly it's a crappy carb that only runs well on choke. That said I'm a professional mechanic and know how to adjust one, etc..

Maybe I'll get lucky and this engine will turn into a Honda someday? :D

kantuckid · December 28, 2021, 08:55:50 AM

Quote from: Southside on December 28, 2021, 08:51:21 AM
Sounds like a fuel obstruction. Maybe filling the tank jossled some junk around and it got sucked into the pickup tube. I would try a fresh fuel filter and see if you have good flow coming out of the fuel lines, if not clean them out or replace them.

Great advice.
I use automotive fuel filters (and larger than OE oil filters too) that are larger, cheaper and clog less.

Maine Miller · December 28, 2021, 09:00:07 AM

Maybe try a little Sea-Foam. Definitely sounds like lack of fuel. Maybe got a little sip of water from the bottom of the tank.

Old Greenhorn · December 28, 2021, 09:17:54 AM

Pull the air filter and see if/how it runs. Could be water or ice crystals in there causing issues or adding water to the mix. I know it's dry there, but this is a quick easy check.

farmfromkansas · December 28, 2021, 09:38:22 AM

The Kohler engine on my Cooks mill acted like that once, I put some seafoam in it, and the more I ran it, the better it ran. Mine sits for months at a time, usually just use it during winter.

newoodguy78 · December 28, 2021, 10:34:25 AM

Seafoam is great stuff. Had a couple irrigation pumps this summer acting like that. Swapped out the fuel filter and gave them a healthy splash of seafoam all issues disappeared.

kantuckid · December 28, 2021, 11:18:25 AM

Seafoam definitely works-and it's mentioned a gazillion times, or more?, on my motorcycle forum. That said it's sure not a cure-all. As a mechanic, it was not my common fix but a lazy try item.
Since today I'm spitting up big gr :

::)n gubers might be Seafoam time for this old fart?

flyingparks · December 28, 2021, 11:37:59 AM

New fuel filter and seafood. Heard it a million times, first time using it. Mill is back up and running! Thanks y'all!

Andries · December 28, 2021, 12:06:58 PM

Quote from: flyingparks on December 28, 2021, 11:37:59 AM. . .New fuel filter and seafood. . .

It's so true, that every thread is about food.
( just kidding ) my mill gets a healthy regular dose of seafoam too, especially in winter.

ladylake · December 28, 2021, 12:43:46 PM

When you filled the tank did you use the quick couplers, if so maybe you have a bad o ring in them. Steve

flyingparks · December 28, 2021, 12:50:26 PM

Quote from: ladylake on December 28, 2021, 12:43:46 PM

When you filled the tank did you use the quick couplers, if so maybe you have a bad o ring in them. Steve

I'm not familiar with quick couplers for fuel, so no.

Quote from: Andries on December 28, 2021, 12:06:58 PMIt's so true, that every thread is about food.
( just kidding ) my mill gets a healthy regular dose of seafoam too, especially in winter.

;)

ladylake · December 28, 2021, 12:55:38 PM

\

Quick couplers unhook the fuel line so you can take the tank off the mill and fill it. Steve

Dave Shepard · December 28, 2021, 12:59:41 PM

I don't think the LT15 has a removable tank, it's just the factory tank on the engine.

flyingparks · December 28, 2021, 01:34:53 PM

Ah yes, my friend has those quick couplers on his LT40. Sadly, I do not.

luap · December 29, 2021, 04:14:56 PM

Quote from: flyingparks on December 28, 2021, 08:35:52 AM
Greetings All,

I was doing some holiday milling and things were going great. Then I shut the engine down after milling a nice log. I refilled the tank with some new ethanol-free gas, the same stuff that was in there already in the tank. The mill had trouble starting. I waited and enriched the mixture, basically choke full on. Then it started up just fine. But it cuts off when I lean the mixture. It won't run at all if I lean the mixture, but sounds pretty good with the choke fully on. Any ideas? My first thought is a sensor issue of some sort. It has been running just fine for a year or so. Kohler G18 engine. Altitude: 7,000 ft. Temp: just above freezing. Any ideas are greatly appreciated. The lady is excited for her she shed.

classic symptoms of obstruction of main jet. remove the bowl and main jet can be unscrewed from carb. Inspect the jet, it will have a series of very small hole around its diameter that are easily blocked with debris ,clean the jet and the bowl with any carb cleaner from auto parts in a spray can. wouldn't hurt to have a new bowl gasket on hand before you start.