425 Problem

[pajoube]

Had a problem with carburetor float sticking so ordered a carb kit and had the local Koehler dealer install the kit.
Went to mow and found I was unable to get full power when under load. All else seems ok but rpm's seem little low. In checking the manual there is no adjustments for this carb. I did adjust the throttle linkage but that did not seem to help.
Did mow today but still not at full rpm's when under load so mower is sluggish and going up incline very slow.
Not sure what to check any more, any suggestions?
PJ

 

[MossRoad]

Hi Paul. Are there any governor settings that could have gotten put back incorrectly? As I recall, some engines have several places where the governor can attach. Might be worth looking in to.

 

[pajoube]

Hi Paul. Are there any governor settings that could have gotten put back incorrectly? As I recall, some engines have several places where the governor can attach. Might be worth looking in to.

Only two rods and one spring to detach when taking the cab off and only one hole for each. With my knowledge of engines I elected to have shop install the carb kit so would assume they did so correctly. Putting bak on was easy and assume was correct with so little to attach.
When the float stuck I had fuel in the oil, muffler, and every where else. Checked today to see if I could smell any fuel but did not.
When starting to mow and oil is cool it seems to run better but when it gets hot it starts to get sluggish, that could also be part of the problem. All this started when carb float stuck.
When working 425 without PTO it works very well with power to spare.
PJ

 

[MossRoad]

I've got the service manual for your engine. In the troubleshooting area for the fuel system and governor it lists condition 3. as "Engine runs lean(indicated by misfiring, loss of speed and power, governor hunting or excessinve throttle opening)." Does that sound correct?

 

[SnowRidge]

Pull the plugs immediately after operating under load and look at their condition. If the engine is running too lean, which it sounds like may be the case, the plug(s) should show it.

If it is too lean, take it back and stand over them while they fix it. Having a death grip on large, hard object while sporting a purple complexion helps immensely.

 

[J_J]

Had a problem with carburetor float sticking so ordered a carb kit and had the local Koehler dealer install the kit.
Went to mow and found I was unable to get full power when under load. All else seems ok but rpm's seem little low. In checking the manual there is no adjustments for this carb. I did adjust the throttle linkage but that did not seem to help.
Did mow today but still not at full rpm's when under load so mower is sluggish and going up incline very slow.
Not sure what to check any more, any suggestions?
PK

Hi Paul, Is your home above 6000 ft? If so, there is a high altitude jet kit available. On the fixed jet carb. Kohler, says the low speed jet is set at the factory, and normally do not need any further adjustment. If you have to install the high altitude jet, and it still does not work correctly, I would go back to the adjustable jet, new float needle and seat. and tune according. If you have the fuel cut off solenoid, be sure it is throughly cleaned. Just a little bit of crud will keep the engine from operating properly.

 

[pajoube]

I've got the service manual for your engine. In the troubleshooting area for the fuel system and governor it lists condition 3. as "Engine runs lean(indicated by misfiring, loss of speed and power, governor hunting or excessinve throttle opening)." Does that sound correct?

David,

All sounds correct except for misfiring.
PJ

 

[pajoube]

Hi Paul, Is your home above 6000 ft? If so, there is a high altitude jet kit available. On the fixed jet carb. Kohler, says the low speed jet is set at the factory, and normally do not need any further adjustment. If you have to install the high altitude jet, and it still does not work correctly, I would go back to the adjustable jet, new float needle and seat. and tune according. If you have the fuel cut off solenoid, be sure it is throughly cleaned. Just a little bit of crud will keep the engine from operating properly.

J.J.
We are at 4700 feet.
I have the fuel cut off solenoid that has never been taken off or opened up.
When mowing yesterday I filled up the tank which lasts for one mowing plus a little extra. I ran out of gas when just finishing. Used more than normal.
PJ

 

[pajoube]

I took out the plugs and cleaned. When finished mowing I looked at them and they seemed to be still in good order.
PJ

 

[J_J]

J.J.
We are at 4700 feet.
I have the fuel cut off solenoid that has never been taken off or opened up.
When mowing yesterday I filled up the tank which lasts for one mowing plus a little extra. I ran out of gas when just finishing. Used more than normal.
PJ

PJ, If you pull the choke out a little does it make any difference? I have used the 20, 22, 25 HP Kohler's, on my Dixie Choppers, and keeping the fuel solenoid clean, and water in fuel was about my only problem. Recommend you take it out and clean it . Maybe the service guy did it for you .