"2005 model" does not really describe how long you have actually had it in order to have put 22 hours on it. But let's assume you bought it in 2005. In nearly 4 years you have accumulated 22 hours of use. That is just 5.5 hours per year. It sounds to me like the machine mostly just sits idle, precipitating varnish in the carb and fuel system. You need to use a gasoline stabilizer additive to your gasoline. You should also add some Marvel Mystery Oil or similar "upper cylinder lubricant" to your gas because this will minimize the chances of an intake valve sticking to its valve guide during the long storage times. What you just experienced was probaly a "soft, gel-like plug" of varnish that was restricting the main jet in the carb. That you could only keep it running by applying the choke indicates it was "starving for fuel". You probably helped dissolve and loosen the obstruction with the fresh gas (fresh gas is more "solvent" than old, unstabilized gas). Your luck can't hold out forever with the limited use you give the tractor. Unless you start adding stabilizer to your fuel you will need to tear into the carb to give it a thorough clean-out at some future date. Products such as Sea Foam will increase the "solvent" action of your fuel and it also will stabilize your gas. It is still a good idea to add the upper cylinder lube to the fuel in addition to any stabilizer you use.

Yes, I bought this unit new in August of 2005 as I have two acres to mow.
However, with the drought here in Southern California the weeds didn't grow that much these past several years so the tractor stayed in the shed and I used the string mower in areas that did grow.
I do start it periodically and run it around the yard.
it seemed like the gas just went bad very quickly or like you mentioned a little varnish caused the problem.
I should have used a stabilizer as ironically I do have some in the garage.
I use Marvel Mystery oil in all my cars as I buy it by the gallon, but wasn't sure if I should put it in the Kohler.
I will add some to tractor gas now. Thanks for the tip.
I had the same batch of gas in my chipper/shredder and my string mower that was in the tractor and they both started and ran fine. One engine is a B&S and the other a Tecumseh.
It was just the tractor that gave me trouble.
The tractor sounds OK now so I probably didn't do any damage to the valves.
Would you suggest leaving the tractor dry by running the gas out when it sits for awhile or keep the gas tank full and use the stabilizer and MM oil?
Thanks for the advice.

If the tractor "sounds OK now", you dodged a bullet (and certainly did not bend a valve or a pushrod). Be aware that there seem to be more occurrences of "stale gas" and "sticking valves" with the gasoline formulae being marketed now (and the blend changes seasonally as well) than what we saw years ago. It might just be me thinking this (because one tends to remember the bad stuff more easily than the good). I have had one "close" experience (but have read of several others) with a Kohler engine in a Kawasaki Mule where the intake valve stuck and the pushrod fell out of the rocker arm when the engine was started after a period of storage. It belonged to a friend and he was lucky enough to be able to reinstall the undamaged pushrod (using nothing but his fingers to depress the intake rocker arm to re-insert the pushrod) and the engine is doing fine now. He now stabilizes his fuel and adds some Marvel oil in as well.

Mownie,
Thanks for the tips and I will follow your instructions.
You are right about the quality of gas as I have noticed that is degrades faster then years before in the cars as well. I have to pull the gas tank on my 67 Mustang to replace the sending unit and I think I will probably find varnish in the tank.

Could be the amount of ethanol in today's gas. Ethanol is a sponge to H2O. Gas stablizer is a fresh container of gas would make the gas be usable for months, not weeks.

I checked the Sears website and they have stabilizer that they say will keep gas fresh for 2 years.
That seems like a rather long time to me.
What is a good stabilizer to use and how long will unused stabilizer keep if kept in its original container?

Just now getting back. bames, in regard to your question of "run dry vs. leave full". I prefer to keep the tank full of fuel (stabilized and MMO'ed) because the greater the volume of air (headspace) above the fuel, the greater will be the rate of exchange (breathing) through the tank vent due to thermal changes. As indicated often (and again by skippymud above), ethanol is a "sponge" or magnet for moisture. The problem with a low fuel level is that when atmospheric air (and moisture) is drawn into a fuel tank during a "cool down", the water vapor is captured by the ethanol and is held somewhat in a temporary solution. If this "loose emulsion" is promptly processed through the engine and combusted, you might not see any ill effects.....this is what happens in the gas powered vehicles we drive to work on a daily basis. But, if the vehicle sits idle for an extended time, the loose bond or "affinity" between the ethanol molecules and the water molecules fails when the temperature rises enough for some of the ethanol to "evaporate". So the liquid ethanol
molecules vaporize when their specific vapor point is reached. The vaporizing ethanol molecules drop the water molecules like a "bad habit" and the formerly "bound" water molecules are free again (because the temperature is not high enough to evaporate water). When the temperature falls again, the water will re-bond with any ethanol molecules that recondense. This process continues until most of the ethanol has been driven out of the tank. During this time, the fuel tank will have accumulated a fair amount of water. Keeping the tank full of stabilized gas means that there is less exchange of air into and out of the tank, and a greater amount of liquid fuel means that any unavoidable moisture will be held in "suspension" longer because of the greater amount of ethanol remaining over a given time. I hope that the ethanol mandate (for ethanol to be in all pump gas) will result in the stabilizer makers modifying their formulae to inhibit the loss of ethanol evaporation (if this is possible). One way the end user (consumer buying the gas) might combat water that condenses in the fuel tank would be to add a "shot" of "Dry Gas" additive to the tank of fuel prior to the first use of the machine after it is brought out of storage. It is almost too soon to tell how ethanol will "corrupt" the machinery while it is stored in the off season, but so far it appears that it "won't be good".

Mownie,
Keeping the gas tanks full in all my cars and garden equipment has been my practice for many years. I have never had any problems up until the ordeal with the tractor.
However, as you mentioned gas is not what it used to be.
I went out today and mixed a half gallon of fresh gas with Marvel Mystery Oil and ran it through the tractor until it stopped. I ran it up and down through the RPM's and it never faltered once.
The engine sounded great.
So I'm comfortable that all is well with that machine.

Now for the cars, I have 6, two of which are show cars and they do not get driven as much as they should. I keep the tanks full all the time and when I do take them out for a run I usually put 50 to 60 miles on them and then top off the gas tanks before parking them again.
Two of the other vehicles are driven regularly and no problem there.
The last two are driven semi-regularly and no problems there either.

I plan to take the two show cars and give them a good run, but I'm not sure what to do with the gas that's in the tanks now.

Plan #1 is to siphon the old gas out of each and refill them with fresh gas adding MMO and Sta-Bil.
Take them for a run and then top off the tanks adding more MMO and Sta-bil before parking them.

Or plan #2, would be to put Sat-Bil and MMO in the old gas that's in them now and just run that gas completely out. Sta-Bil says it will dissolve varnish, if in fact I have that problem.
I would then fill the tanks up and add the Sta-Bil and MMO before storage.
What would be your procedure?
BTW, does Sta-Bil have any negative effects over the long run?

PS. So far there is no ethanol in our gas here in California that I know of.
I use Chevron exclusively.

You may be correct that Cali has somehow avoided (or "resisted") the ethanol infusion that many other people in other areas are now having to deal with. Or it may be that Cali does not require disclosure labels to be prominantly displayed on the pump if ethanol is used in the formula. I can only affirm that here in Tenn, the presence of ethanol in the pump product MUST be declared by a label that must be affixed to each pump that dispenses gasoline. Additional signs elsewhere on the property are allowed but not required (as if someone would "brag" about ethanol being in their formula). About the negative effects of stabil for the long run: It has been "reported" or mentioned in this forum that stabil itself MAY deteriorate and form some type of "waxy crystals" in the unused portion of the bottle while on the shelf after having been opened and partially "emptied". I myself have never seen this occur and I have no idea what other factors might (or might not) have been involved in the reported cases. I can say this though: Years ago (in the 1990s) I was going through my dad's tools and things some 6 or 7 years after he died. I found a half full bottle of Stabil and brought it home with me (along with a bunch of other things that Mom wanted "hauled away"). I put the box that had the stabil away in one of my sheds and sort of "forgot it". After I read a posting here about the "waxy crystals" I thought of that old bottle of stabil (and it had to be "at least" 16 years old at that point). I was curious, so I dug out the old bottle to examine. The stabil appeared to be the same as what was in my "current supply" except maybe just a tad "redder" in color. In fact, I emptied the contents of the old bottle into my "new" bottle and used it with no apparent ill effects. In regard to "What would be your procedure?"
If I was dealing with your set of circumstances, I would probably be be tempted to pump or siphon some (or all) of the "older" gasoline out of the "least operated" vehicles and add that fuel to the tank of a vehicle that gets driven daily (or at least "driven often"). That practice might present a new set of circumstances though. If you do mix "old, stale" gas with new gas, it should be at a ratio of not more than 50% old gas to 50% new gas. There are no hard facts to support this......this just seems to be a general consensus as MANY folks already "rotate" their stock of old gas by putting it into the tank of a "driven daily" vehicle in their "fleet". If you already have a way of "storing" or "holding" a volume of fuel safely, you could develop your own schedule for "refreshing" the fuel in your "seldom driven" show cars without much trouble or added expense. It will require a bit of effort, but if you have show cars......effort should alread be a buzz word to you.

Mownie,
Great idea and I will go with it.
I have priced Sta-Bil in my area and what surprises me is that an 8 ounce bottle costs $5.98 and a 32 ounce bottle costs $12,99.
A great savings on the larger bottle, but that means it will be on the shelf longer.
Anyway, I have to remove the tank on the Mustang to replace the sending unit so draining that old gas out will be a must in this case.
There is a trick to replacing the sending unit without removing the tank, but its just that, tricky as the muffler is in the way.
The Pontiac I will drain and put in a few gallons of fresh fuel with the Sta-Bil and MMO and run that for awhile and then fill completely with fresh gas and the MMO and Sta-Bil.
Apparently the Sta-Bil is supposed to dissolve the varnish, right?
Thanks for all the advice and I will let you know how it all comes out.

Barnes - one thing to keep in mind when supersizing the Stabil product... cuppla yrs ago I got a small 8 oz bottle - used 1/2 of it - and 6 months later when going to use the balance, saw where it had developed small suspended flakes that made me stop just before adding it to my tractor's fuel tank. Later, saw a post or two on the tractor bb's noting similar experiences.
Your choice. I have heard of another treatment called Seafoam...

bames, I do not see where Sta-bil will "dissolve" varnish. Sta-bil claims to "prevent" formation of gum and varnish by preventing the "formation" of gum and varnish that occurs when unstabilized gasoline separates into the constituent compounds that that are blended to create what we call "gasoline". When the blended ingredients are left standing in storage, they will begin to separate and/or stratify. Some of the more volatile liquids will evaporate out of the solution and disappear into space. Some of the other components will thicken and gel if allowed to separate and stratify. I believe the principle that Sta-bil is meant to prevent (or at least, "slow" the evaporation and separation of gas. I don't know how it accomplishes that, but I believe that's the trick. Seafoam, on the other hand, DOES dissolve varnish. Here is a link to the Sta-bil website.

Here is a link that might be useful: A stable relationship

And here is a link to the Seafoam site. Remember this, ALL the products and chemicals are for SALE. Same as for the Sta-bil website. A lot of what you read is a "Pitch". Nothing wrong with that....just keep in mind that these are not "objective reports" but are to promote a particular entity's "product". Read and decide.

Here is a link that might be useful: see foam? yeah, I see it

mownie - how much of the MMO do you mix in with the fuel? I've been using Stabil forever, but might try the MMO if it's a safe way to keep this engine from locking up.

Using the cap that is on the bottle, I add 1 capful per gallon of gas. That is probably about 1/3 fluid ounce. You could likely add 3X that amount per gallon and not notice anything (smoke) in the exhaust or on a spark plug. I mainly use it as a precaution against the possiblity of an intake valve sticking during storage. That occurs when the gas that gets on the intake valve stem (it's exposed in the intake passage) evaporates and leaves sticky residue that does not evaporate but can actually begin to "crystalized". The idea with the MMO is that when all the volatiles evaporate out of the gasoline film, there will be a light film of MMO remaining on the valve stem that spoils the "stickiness" of the other residues. It does not require much MMO to achieve a light film and that's all that is required. Another possible benefit of adding some MMO is that it will leave this light oil film on all surfaces of the fuel system, providing some lubrication and corrosion prevention for those components.

I've used Stabil a couple of times in a few of my Briggs and Stratton engines, and for whatever reason, I had a dickens of a time getting those engines to run properly. This was following the directions on the bottle too.

I had to drain the gas, put new gas in, and used Seafoam instead. Big, big, big difference! The engines ran smoother, and the plugs seemed to stay cleaner too.

I also run Seafoam in my 2007 Toyota Matrix and my 1977 Chevy Nova with a 305 V8. Both of those cars run like tops.

Maybe it is the gas in my area where the Seafoam shines and the Stabil doesn't. I certainly don't have a clue, but I buy Seafoam as the only gas treatment that I use. It has been out since 1942, so it should have been thoroughly tested by now.

Now you got me confused.
I went out and bought a 32 ounce size of Sta-Bil and then I read what you guys had to say about Seafoam.
Should I go and get a can and use that instead of the Sta-Bil?
If it does dissolve varnish then I could just dump a can in each car with the old gas and take a long trip and burn it all out right?
Then would I use the Sta-Bil with the new gas I put in the tank. or keep on using Seafoam and take the Sta-bill back to the store since I haven't opened it yet.
Does Seafoam work the same as Sta-Bil as a stabilizer for storage?

Well, I did some further checking and here are two sites that discuss the issue further.
I guess its 6 to 1 and half dozen the other as to which is best.
Seems they both work very well as stabilizers, but Seafoam does a better cleaning job.
Still not sure which to use, whether it be either or both.

http://www.idofishing.com/forum/showflat.php/Cat/0/Number/255335

http://www.kawasakimotorcycle.org/forum/kawasaki-cruisers/93662-stabil-vs-seafoam-gas-stabilizer.html

Use 'em both at the same time... Can't go wrong then.

Ditto what rcbe said, I've done that too.

Great,
I think I'll take out as much old gas as I can with a siphon as its very old gas and put in 4 or 5 gallons of fresh gas and add the Seafoam.
Start it up and let it run for awhile and shut it down and let it sit for a day and then take the car for a run until it gets close to empty and filler up and add the Sta-Bil. Do you think by letting it sit for a day that any build up of varnish in the fuel lines and carburetor will be cleaned out or will it take that long, or longer?
I will do this for both cars.
Thanks much for the advice. You are all very knowledgeable.

Sounds like a plan! I would think that driving would hasten the removal of any varnish with the jostling and swirling of moving fuel. If you want to start the vehicle and let it run to get the new mix into the carb (and then let it sit for a day or so), that will work best if you at least move the vehicle forward and backward a few times (tap the brake to stop before going the opposite direction) after you pour the new stuff into the tank. This way you can be sure you are getting the "good stuff" into the fuel lines and onward and not just some more "old stuff" hovering around the fuel pick up.

I got a couple of can of Seafoam today at Kragens so I will start the process this weekend.
The sales guy at Kragens told me that the Seafoam was great stuff and he uses it all the time.
He also said that he had heard that the EPA in talking of banning it in California by this fall.
Has anybody heard anything about this.
It wouldn't surprise me as California can't leave nothing alone.
I may got back and buy several more cans before they run out if this is indeed true.