Kohler 25 Hp fuel problem? UPDATE:

[gump]

Wondering if anyone can help me. I have a Woodmizer LT15 Wide with a 25 hp Kohler Commander engine. It seems like it is not getting its fuel. If the mill sits for a while it will not start. The fuel filter is only about 1/2 full and will not fill up. I placed an in-line  fuel pump (like one on a boat rubber squeeze bulb type) and that doesn't seem to work either? When I put a bit of fuel directly in the carb it will start and run with the choke on, and run forever this way. Once I disengage the choke the engine dies! HELP.
Although I have had this mill for awhile, this motor only has about 30 hours on it!

[ladylake]

 
Some Koehler's have fuel shutoff solenoid in the carb that might be sticking.  Steve 

[Gere Flewelling]

Hi gump,  Have you made any changes to your fuel tank lately?  Sounds like you could have a venting problem.  Not letting air into the fuel tank.  Next I would see if your squeeze bulb is actually pulling fuel out of the tank.  Possibly a clogged filter in the tank.  Remove the fuel line from the engine side if the squeeze bulb and see if it will pump gas into a container.  If all is good from there, I would suspect there is contamination in the carb. that is either blocking the needle valve from opening or something in the float bowl that is blocking the fuel from entering the main jet.  If the unit has an electric solenoid on the bottom of the float bowl, see if it has 12volts going to it with the key in the run mode.  If not you will need to trace out why.  Could have a bad connection or fuse.  This solenoid is designed to shut off the fuel when the key is shut off to not allow fuel to be drawn in when engine is shutting down.  This to prevent engine backfire.  I have seen those get corroded and clogged, but usually on an engine that has set for a long period with old fuel in the carb. An air leak between the carb. and manifold (bad gasket) could give similar issues.  When cold the mating surfaces leak by and when warmed up the gap (leak) seals up some.  These are a few things to look for from my experiences.  Good luck with your diagnosis. GF

[gump]

Thanks guys..
I took the fuel line off the engine side of the fuel filter and squeezed my pump..All good. lot of fuel going through the filter when I do this.
If the shut off solenoid is not working and is stuck in the shut off position would my engine not start at all? It does start and run with the choke on.

[doc henderson]

On small engines in general, when you have to run with the choke on or half on, it is often gunk/varnish that has altered the function of the carb.  you need a proper air fuel ratio to run, and you are saying "it needs less air to run" (choke).  clean/rebuild/replace the carburetor.  I have a thread somewhere about the half full fuel filter.  this seems to be a thing that everyone has that does not bother the flow of fuel.  although, some only see the filter as half empty.   :D :D :D  you can try some seafoam if you like.  That will work if things are not to bad, but prob. better to find the problem and address head on if you want it to run dependably.  I would pull the carburetor off and check the bowl, and pickup tube as well as all gaskets.

[gump]

Thanks Doc.
Thats what I'm thinking too. I do use fuel stabilizer in my fuel to help with that. I'm not a big fan of seafoam, but I will change out fuel and add some to the new tank and see what happens. I really want to avoid pulling the carb if I can.

[doc henderson]

sometimes a good spray of carb. cleaner can help if it is not too bad.  lots of small passages.

[Sixacresand]

I recently experience a fuel problem with my Kohler/Woodmizer40.  The fuel filter bowl would not fill.  The engine has a fuel pump which pulls (sucks) gas out of the tank.  After doing some quick research on the FF, I found the fuel line quick connect at the tank had a failed Oring and sucking air, instead of fuel.  The quick solution was to bypass the quick connect.  On a side note, WM recommended using 100% gasoline (non ethanol) which I do on all my small engines.  

[esteadle]

I've had a similar problem and it was pretty maddening. 

I'd first check the fuel solenoid as others are suggesting. it's near the front of the carb. You can trace the wire to it and make sure it's not shorting out. It needs a good solid ground to function properly, so remove the 2 screws and clean everything well and maybe coat the ground contact points with di-electric grease before reinstalling. 

Also check your ignition key switch and make sure it is providing the power to the solenoid. There are wiring diagrams in the Service Manual for your engine which are available for download at Kohlerpower.com. 


If that doesn't do it, pull the carb and give it a thorough cleaning. Order a seal replacement kit. The seals in mine were way old and needed to be scraped off and replaced. A new carb is about 300 so try to save it first. 

The half full fuel filter is not a problem as long as you are using the right filter. Pull the fuel line off the engine after the fuel filter and run the pump, and you should see plenty of fuel run out. 

I cut the fuel at the end of the day and run it dry. I do that to avoid stale fuel issues in the carb. Fuel stabilizers are not that effective in my experience. 

[Gary Davis]

I had the fuel solenoid stuck in the open position no reason it could not be stuck in a partly open position, easy to check and clean if dirty    

[farmfromkansas]

I let my mp32 sit too long, without starting, and then ran poorly.  Added seafoam, and filled it with gas, and started sawing, longer I ran the mill the better it ran.  Same 25hp engine.

[Chuck White]

I have the same engine, but I only use 91-octane, NO ETHANOL!

The only issue I've ever had with mine is that it doesn't like cold weather, if it gets down into the lower 50's, I cover about 3/4 of the air intake grid!

The fuel filter will not fill, only gets about half way, that's just the way they are!

When you're done sawing, disconnect the gas line from the fuel tank and let the engine burn out whatever fuel the is in the line and the carb!

[Gere Flewelling]

I think it is possible for the solenoid to stick in a position that would allow some fuel through if there is enough vacuum like when the engine is running from gas dumped in the carb.  Had a Briggs Vanguard 16 hp on my splitter that did that very thing.  Would only start cold by squirting fuel in carb.  Once warm it would start better.  Ran it for a few years this way until it got worse. Took carb apart several times looking for dirt.  Never really found any.  Finally tried a used carb off an identical engine on my other splitter.  Engine started fine.  Started going deeper into the original carb. Found main jet that is fed through the shut down solenoid seized in the carb. No getting it out.  Ended up with a third carb off another engine (these are old lawn mower engines) and cured my problem.  I think there was an issue with that solenoid but never could identify just what.  Another thing to try would be to spray some carb cleaner around the outside of the carburetor when the engine is running.  If the rpm's change , that means it is sucking air/carb cleaner in through a leak.  Carb cleaner burns but not as well as gas.  

[esteadle]

Kohler says: 

Engine Starts But Does Not Keep Running 

Faulty carburetor. 
Faulty cylinder head gasket. 
Faulty or misadjusted choke or throttle controls. 
Fuel pump malfunction-vacuum hose clogged or leaking. 
Intake system leak. 
Loose wires or connections that intermittently ground ignition kill circuit. 
Quality of fuel (dirt, water, stale, mixture). 
Restricted fuel tank cap vent.

I think the FF community has covered a majority of those bases. 

[gump]

Thanks everyone for your help. 
Next week end I will bring in "carb cleaner " spray, "seafoam" (uggh) with new fuel. Initially I will try that. If not I will pull the carb and clean.
I've always used high octane fuel and will continue doing so with stabilizer added to it. Once this problem is resolved I will run my engine dry of fuel once I am finished sawing.
It's a bit of a pain being so far away ( 2 hour drive) from everything for stuff like this! But that is the trade off for being way "off grid".

[shelby78]

Thanks everyone for your help.
Next week end I will bring in "carb cleaner " spray, "seafoam" (uggh) with new fuel. Initially I will try that. If not I will pull the carb and clean.
I've always used high octane fuel and will continue doing so with stabilizer added to it. Once this problem is resolved I will run my engine dry of fuel once I am finished sawing.
It's a bit of a pain being so far away ( 2 hour drive) from everything for stuff like this! But that is the trade off for being way "off grid".

I would bet money its the fuel solenoid. My lt15 wide is 2-3 years old and it has done it since year 1. I only run high test in any small engine. Grab a long screwdriver/wrench/piece of steel and tap the front of the carb a few times. I bet 10 bucks she fires right up after.

[gump]

Came back this weekend with new fuel, seafoam spray and seafoam liquid. Got the motor started with a splash of fuel in the carb with choke on. Same thing happened..would not run with choke off! SO.. I sprayed Seafoam down the carb,  several times, didn't seem to do much. I then lightly tapped the side of the carburetor with a screw driver and the engine suddenly stopped!! Took the choke off and tried to start it and it flashed right up!! Running fine all morning, go figure. Not sure what exactly the problem was but leaning towards sticky solenoid . Thanks for all the input guys.

[shelby78]

Nice to see the update.. Mine will run all day start and stop fine. If it sits overnight I have to tap the carb. It seems to be a common problem with these engines and in my opinion a poor design..

[Durf700]

so whats the fix?  does it need a new carb or what?  I have the 25 HP Kohler also.. so far so good but want to know what to purchase when /if this happens.

[shelby78]

so whats the fix?  does it need a new carb or what?  I have the 25 HP Kohler also.. so far so good but want to know what to purchase when /if this happens.

I don't know what the fix is. I just tap the carb if it doesn't start (Which is every time if it sat for more than 12 hours) This is on a low hour mill I bought brand new. Only ever seen 91 or higher octane. If the carb is tapped or the mill has been running it will run in half a crank..

[gump]

so whats the fix?  does it need a new carb or what?  I have the 25 HP Kohler also.. so far so good but want to know what to purchase when /if this happens.

I don't know what the fix is. I just tap the carb if it doesn't start (Which is every time if it sat for more than 12 hours) This is on a low hour mill I bought brand new. Only ever seen 91 or higher octane. If the carb is tapped or the mill has been running it will run in half a crank..

Ditto>>

[kantuckid]

Stihl says 89 or above to keep yer warranty but on my WM Kohler I use 87 as I also use in most other small engines except for the 2 cycle which I mix in one gallon batches to keep it fresh. 
So fa I've replaced the fuel filter several times and first change out I went to a much larger filter intended for and automobile. Just but the cheapest, biggest one you see in Walmart with the right diameter connections.
Oil filters I do the same, I buy the biggest ones that fit that Kohler engine correctly in the guts section as there's plenty of room to stick out plus more filter equals more filtration and I could car less what brand they are-I buy FOMOCO's for my truck & car but Kohler gets Wally's brand.
Seafoam does work as a cleaner which is it's main role in life. I don't think of Seafoam as a fuel storage goop!  
We all know ethanol has kept small engine shops in business lately but if you use a proper fuel treatment or run fuel that is kept fresh by frequent use your components will be OK. 
Since I only saw for myself(most always) I use Marine STABIL. 
I am a nearly 60 years motorcycle rider and fuel is a very worn out subject on MC forums as many store their bikes in winter climates. many keep "pure gas" at home to feed their precious motorcycle, I never do that exception is my Vespa 300 GTS scooter which calls for high test 91-93 octane and I do adhere to that fuel rating as that engine is designed for that fuel. It runs at high tempos and a very high power per cc is being wrung out of it so unless you want to buy a new engine it matters for longevity. However they run sort of OK on 87 in a pinch until one sees the good juice. Marine STABIL vs. it cousin the regular stuff which is not as good. Another factoid is to not buy/use STABIL which comes in large containers unless your a mega user as it must be fresh just as gasoline suffers from age. Don't we all?
FWIW, I replaced the bad carb on my Kohler with a cheapo Chinese Ebay carb and it runs fine now. The Kohler was like 8-10 times the price point. On the Kohler round air filters-I use filter foam wraps sold for the powersports trade and cut it myself to save money. Besides the mice eat the foam every winter and the engine smells like mouse pith too. 
I also replaced my Kohler OE fuel shutoff-the red plastic one- with a Chinese  kit that fit into the tank, etc. just fine and still works. 
The hour meter gave up long ago and the cheapo Chinese version I installed never worked so I simply change oil seasonally now-new when I quit sawing, etc.. My Kawasaki Mule calls for oil ~ 50 hours but it gets oil a tad sooner as it's engine is a water production device! abd oils get saturated via extreme condensation earlier than 50 hours. My Kohler oil, OTOH, seems to stay quite normal in appearance.
I wrenched for a living so love a gearhead thread as if you can't tell... :D 
  

[Skip]

X2 on the Marine Stabil . 

[booman]

If you have to tap the carburetor to get it to run, sounds like the float is sticking and tapping causes it to break loose.

[kantuckid]

I'll throw in this tidbit on my Chinese Kohler carb- the float bowls made from almost b ;D ;Dr can thickness alu and would not stand much pecking! In fact one must be careful tightening the bowl screw to keep it sealed...