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Discussion Starter · #1 ·
(or, Seafoam is not a wrench)

I've always been happy with my 2006 YS-4500 with the Kohler Courage 20hp single cylinder engine. It has always started easily, at idle, with no choke, had plenty of power, used very little fuel, and was a smooth as a 20hp single cylinder could be expected to be.

I don't do a whole lot of maintenance to it, basically 25-hr oil changes, and annual air and fuel filters, as well as a general cleaning and tightening of the top cover bolts. Last year, I thought I'd be clever, and replaced the fuel filter with an automotive one - after all, it's $3 cheaper and just as good, right?

Well, this year, it started to drop in performance a little. Initially, it just needed a little more cranking time, and there was an occasional miss at idle. Then it started missing at speed. Then, about 4 weeks ago, I went to start it up and the engine had hydrolocked with fuel in the cylinder. Clearly, there was some crud in the carburetor that was hanging up in the needle valve.

That really didn't make sense to me, since the fuel filter was only about 6 months old, but when I went to inspect it, the downstream side of the filter had separated from the body, letting unfiltered fuel straight to the carburetor. My guess is that the automotive filter couldn't stand the vibration of a small engine - the way the fuel line is plumbed, the filter actually rests against the engine block. I replaced the fuel filter with a Kohler one, and hoped that the crud would eventually work itself out.

Well, it didn't, and the performance kept getting worse. I decided to take the lazy man's path, and put about 1/3 can of seafoam in the gas tank to try and clean the carb from the inside. Almost immediately, the idle smoothed, and the miss was gone. It had plenty of power from idle to full throttle. I mowed the lawn, and before I shut it off, I cycled the ignition a few times at full throttle to work the anti-backfire solenoid and hopefully flush any other residual crud from the carburetor. I thought the problem was solved, and I was singing the praises of seafoam as I put the tractor in the shed.

Well, yesterday, I got the tractor to take down to the MIL's to mow her yard and wouldn't you know it, the cylinder and crankcase were full of fuel. Well, darn. I got it started and nursed it up to my garage to change the oil and drain the oil filter. I know it's not ideal, but I had a job to do and not enough proper oil to fill the crankcase. It ended up with about a 50-50 mix of Rotella SAE-30 and Pennzoil 5W-20. I took it down to the MIL's and mowed her lawn, with the mower running terribly. It was missing at all speeds, couldn't maintain speed, and had way low power, which really sucked since her lawn was overgrown. At one point, it just flat died, but I was able to restart it after 30 minutes or so and finish the lawn.

On the way home, I did what I should have done a month ago and bought a can of carburetor cleaner and a gallon of the proper oil and a new filter. It took me about 30 minutes to dissemble the carburetor. I didn't see any visible dirt, but I dissembled the float assembly, needle valve and idle jet. I blew carb cleaner back and forth through all the passages, and put it back together. The tractor immediately started, running smooth as silk (or at least as smooth as the day I bought it) and all the power had returned.

Long story short, my lesson learned is that seafoam, while it's probably pretty good preventative maintenance, won't remove insoluble physical crud. When there's a mechanical problem, there's really no other way to fix it than the right way - by taking the carburetor apart and cleaning it. It only took me an hour start to finish, and the can or carburetor cleaner was half the cost of the can of seafoam.

(Afterword: When I was mowing with the tractor running poorly yesterday, I noticed something weird. The transaxle temperature, which typically runs
130-140 degrees, ran up to ~160 degrees. It's never run that hot before, and I think it was because the engine was running slower, and the transaxle cooling fan was not running as fast as it usually does. It goes to show you that the whole tractor is designed as a unit, and a problem on one part (the engine) affects the rest of the tractor.)
 

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i have been a firm believer of taking the carb off and cleaning it my self ..I have used a touch of gas line anti freeze in the winter ..But thats it ..But nothing beats a good carb cleaning ..As for the filter no matter what filter you use there is always going to be stuff in there ..Gas for some reason makes little deposits when it sits and the rubber gas line it self will brake down also ..I have seen myself put a brand new carb ,new gas-line,new filter,flush the tank and 6 months later find crap in the bowl ...
 

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Good article - thanks for posting. It's true, there are very few shortcuts to doing it the right way.
 

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Discussion Starter · #4 ·
.Gas for some reason makes little deposits when it sits and the rubber gas line it self will brake down also ..I have seen myself put a brand new carb ,new gas-line,new filter,flush the tank and 6 months later find crap in the bowl ...
I hadn't even thought about that - I've been using gasohol in it since it was new - that may have caused the fuel lines to break down a little and gum up the works.
 
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