Problem...28hp FI Kohler

[Kevin_H.]

Ok guy's put on your thinking hats.

I have a 28hp FI kohler on my WM, she is losing power, starts just fine and will run ok with no load, but when ya start to cut it has no power, it will die in the cut unless you just creep along.

Fuel filters are fine and the fuel pump seems to have plenty of power.

It did have one error code that said the fuel sensor had made it's maximum adjustment.

The possibilities so far are a bad O2 sensor
Faulty spark advance unit or a dropped valve

It will be wed, before I have a chance to put a timeing light on it to see if the timeing is advancing.

Any other idea's?

Replace the gas just incase it had water in it, but it made so difference.

Oh yea also, it will run the same (low power) weither the O2 sensor is plug in or not...

What do ya think?

[SAW MILLER]

I have the same engine on my 05  LT 40 and once in a while it will do the same thing.It idles fine but has no guts when you enter a cut.The problem was found and easily solved with a can of WD40......It was a sticky throttle plate shaft.Since I found the cause I give all the carb linkage a shot of WD once in a while and it runs good but if I run in the rain at all ,thats when the dust sticks to the carb area and it will start sticking again.
  Give this a try and let me know if that fixes it.

                                                                               Ron

[beenthere]

I'll bet Rust Reaper in place of the WD40 will be many times better too....

[Kevin_H.]

Ron that was the first thing I thought of, I have had that same problem, but this time not the case. I can see the linkage working, matter of fact if I grab the linkage and bring it up to speed the motor dose just fine, but If I try to engage the blade it falls on it's face.

We thought the injectors might be partly plugged, so we engaged the blade and then sprayed some carb cleaner in the air cleaner, thinking that if the injectors are plugged the added fuel from the carb cleaner should speed up the engine, but it didnt.

the last time we messed with it tonite, it would bearly run while it was in gear, it was just spitting and sputtering, so maybe it is the "smart spark" spark advance unit that kohler use's.

If I had some place close that I knew could fix it, I would pay to have it done, but I hate to take it somewhere that has never worked on the 28hp FI motor, Kinda like beta testing...

The shop I talked to today said the spark advance was something like $100.00, they think?

anyone else?

[Brucer]

How's the temperature over there?

I've had exactly that problem on my 28 HP FI Kohler. Every time it's been a problem with the O-rings on the fuel suction line connector -- and it only shows up in hot weather. One of the O-rings leaks and let's a small amount of air into the fuel. In hot weather this causes a vapour lock at high engine loads.

Usually it's the O-ring on the outside of the male connector on the tank. You can replace that with any O-ring the same size.

A couple of weeks the O-ring on the inside of the female connector on the hose had a tear on the surface. I replace it with a standard O-ring and after a few days it swelled up from exposure to the gas. Turns out you need a special O-ring that's rated for use with petroleum products, and those are hard to find around here.

There's a quick way to test for this problem -- wrap the connection tightly with electrical tape.

[Kevin_H.]

Brucer, thanks for the tip, it was about 88 deg. or so, I too have had that problem so I switched to a different type of connector, Just to double check I switched the return line with the infeed line and it runs the same, but it is possible that bolth connectors are bad, I will double check that when I make it back to the mill tomorrow. Also I am not getting any air from the bleeder between the fuel injectors

Things always seem to break when you need them the most.  :D

[Kevin_H.]

Ok so here is what we learned today

Compression test: 160 each side = ok
Fuel pump test 40 Psi = ok
New plugs: no change

It doesn't take it long for the muffler to get cherry red inside so we think it is running lean, but why?

the motor will run the same (bad) wether the 02 sensor is plugged in or not so WM is sending a new one...

Big thanks to greg at WM for fielding all the questions today

Any other idea's ?

[Mo]

Greg is very good on our engines. I'm sure he'll get you running smoothly again.

[Kevin_H.]

I have no doubt that Greg and WM will get me up and running again... What a team

[Kevin_H.]

Ok I think we might have it figured out.

We replace the O2 sensor today after the clean up from the storms and tried it again, still no good, no power.

So I pulled the spark plug off the left side and fired it up, it would start and run on the right side cyl. I then put the left side back on and pulled off the right side wire, no go, it would not run at all, so the left side appeared to be the bad side. we pulled off the valve cover and made sure the valves were opening and that we hadn't messed up the lobes on the cam, well they looked ok.

So just out of curiosity I took the plastic handle on my screw and tapped ever so lightly on the fuel rail where it connects to the left side injector and away she went! I put the right plug wire back on put the blade in gear and all was good.

I made a couple of passes and all seemed fine, so I dont have a clue (which should be evident by the first post) what was wrong with the injector but we will run it a couple of days and see what happens.

Big kudos to Greg and WM for all the answers, I can just imagine the guys at tech support, "It's kevin again, whose turn is it to answer the phone" 

[Tom]

Fix'em two pancakes at the piggy roast.  :D

[YellowDog]

I've been having trouble with my Kohler F1 28hp since day one when the weather was hot it would not run last year. replaced the little black box just before the final filter. Now the new one is doing the same thing the old one did. would not go during the run but idlid just fine. I took the box off and have been running without it. Goes good through the run but has a hard time idling.
       I am thinking of buying a second fuel pump and a couple of check valves and putting the other pump on the return line with a check valve then teeing the two lines together before the final fuel filter.
       What do you think?

[Kevin_H.]

Are you talking about the valve with the return line back to the tank? and if so when you take it off what are you doing about the return line?

Have you tried giving WM a call? If they can help me out, I know they can help you.

Hey tom we ran a test run on some pancakes this weekend while camping, so good.

[YellowDog]

      Greg at WM suggested I run the line straight from the fuel pump to the filter, I guess he suspected that that black box was the problem. I called him and left a message that the machine didn't Idle but ran fine through the run. He never called me back after that. Now today I knottiest  the red Alt light and code light is not working. I'll have to call him and get a schematic and figure out what is causing that failure.

[JV]

My 28HP bogged down the other day and finally quit.  Checked everything I could think of with no luck.  Took the suction line steel quick connector off at the tank.  The O-ring inside was the consistency of putty.  Removed it, the check ball, and the spring.  I took the other end of the connector off and connected the hose directly to the tank.  End of problem.  I had the same problem on our boat in the middle of a lake a few years ago.  Those connectors can be a real headache.

[YellowDog]

     I am still having a problem with the fuel regulator, I've blown two and have been running the last week without one. It's very frustrating, Greg hasn't  returned any of my phone calls Steve tells me to talk to greg. I went to Green Bay this weekend an talked to a lot of people about my problem. The right shops where closed but I got web sights. There must be another regulator that can regulate the stream of gas at 40 psi that will hold up!