PTO Vacuum Act./mower slight stall

[chip6990]

i got a '03 GT3235 w/a 25HP Kohler Com. It started losing rpm when i was mowing thick high grass, i noticed i was smoking the PTO drive belt. so i replaced the drive belts and blades. today when i mowed, at first when i engaged the blades, it souned like it was gonna take off like a helicopter, after about 3 swipes, it started losing rpm. the grass was not thick and maybe cutting 1/2" off at most. i gotta stop and let the rpm's come back up before i can continue. if i move at a snails pace, it seems ok, but if i try to get after it at all, it seems it cant keep up. i have the vacuum actuater adjustable rod, adjusted as far as it can go to put the most pressure on the belt. my guess is that its losing vacuum somewhere. this a common problem? any idea are greatly appreciated. cant make any $$$ just crawling.

[chip6990]

i thought i fixed my problem, i changed my spark plugs. 1 was real black and sooty and the other was ghost white. how can one cylinder be running rich and the other lean? the new plugs def. helped with idling, but didnt solve the motor bogging problem. if i am mowing down hill, it dont bog, but if i am level or going up hill, once i apply the gas pedal, it starts dieing down till i have to stop and wait for it to catch up. i thought the vacuum actuator was bad slowing the blades down, but its def the motor. to test this theory, i turned the blades off and went full throttle across the yard. halfway across, the motor nearly stalled and died. any fixes to this problem without going to a cub service dealer or small engine repair shop?

[Sam Mac]

Chip

Sounds like you have one hole that is not firing. Check and see if the one that is rich looking is actually firing, if not you probably have a bad coil. Also sounds like it may be a little lean if the other CYL is white. You may want to post in the engine section something like "Kohler 25 problem". I also see that you posted the same on MTF so I’d also hit the engine section there.

[Matt G.]

I'd first check for a blown head gasket on the side with the plug that's black.

[chip6990]

thanks guys. its hard to find time to work on the silly thing when i work 12-16hr days almost every day. it just recently started acting up like this. i love my 3235 but its driving me insane.

[chip6990]

i had some issues with it running last summer, had some some so called "small engine experts" tell me it was just the carb needing to be cleaned. well they cleaned it alright. it wouldnt even start. i figured out they put the needle jet in upside down and put an o-ring over 1 orafice. i fixed that and figured out that it was the solenoid on the back of the carb that was my problem. so im thinking it has to be carb related.

any detailed links or pictures on how to clean and adjust the carb or gov. on it?

[Matt G.]

Don't dig into the carb just yet...the key here is that you said the plugs look different. It is very unlikely the carb is causing that. A more likely cause is a head gasket as I previously mentioned, or one coil going bad.

[chip6990]

wouldnt a head gasket be a little obvious? what would be the normal signs of a blown head gasket?

[Sam Mac]

Chip

I have a CH22 that I was positive had a bad carb the way it acted. I was so sure I went and bought a new carb. Turned out to be a bad coil. Like Matt said check the head gaskets (do a compression check) if that's OK check to see if you have a good spark on both sides. I'd even get a good pair of rubber gloves and pull a plug wire off while it's running and see if it makes a difference then do the other side. If you have a dead coil it should shut off when you pull the good one.

[chip6990]

i dont have the tools to do a compression test. but i will try uplugging 1 wire at a time to see if it makes a difference to the way it runs.