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Discussion Starter #1
My Craftsman GT3000 about 15 years old is my guess, has run well and recently died when I started it up (easy start) and backed up for about 10 seconds. Engine stopped. Tried repeatedly to restart with no sign of starting. Opened hood and sprayed some carb cleaner in carb and it quickly started, then died after about 3 or 4 seconds. Would not start. My diagnosis is fuel problem, not ignition.

Checked for fuel to carburetor and pump seemed to be working. Pumped a few ounces when cranked for 5 seconds. I had to catch fuel and then look, I didn't have anyone to sit in seat and hit starter. So I next removed the solenoid and found it did operate when the ignition was turned on, and extended outward when the ignition was turned off. My conclusion now is must be the carburetor, seem right? I don't see any reason to rebuild the Carb, rather I'd just purchase a new carb over the web, under $30 as I recall, maybe a few dollars more. Or am I off mark assuming I have also cleared the ignition of contributing to the no start problem. I did not check for spark.

Looking for recommendation on additional testing I should do before ordering a new carburetor. :tango_face_glasses:
 

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I'd do a compression test before ordering a carb. It could be a valve issue. If that checks out fine, why not disassemble the carb and have a look for what the problem might be?
 

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I have almost same mower,22hp with Kiehn carb, expensive,well made,never seen a Chinese knock-off.Carb was difficult to remove,but easy to work on.Small holes in emulsion tube were totally plugged on mine.
 

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Discussion Starter #4
The carb falls of in the hand once the filter and filter mounting are removed. So, easy to get on the work bench suppose it is worth a disassembly and I can take a look on YouTube to get a good look at what to expect. Yes, things can just happen, but as the engine was running smoothly and reliably before the sudden stop it would have to be something like a chunk of dirt stopped up a jet or the like, and as the tractor was not under any load other than a slow backing seems unlikely (to me) a valve spring would break. Then I say that in part because in my 60 plus years as a "shade tree" mechanic I have never seen a broken valve spring. Thanks for the help, but the cost of a new carb is low enough that I can't see doing much frustrating work to try to rebuild mine. As for a compression check I'll have to look for my compression gauge don't remember when I last did one. Got any good numbers for what I should expect for the Koehler engine? Assume all I need is a fully charged battery and both plugs out to get enough cranking velocity to get a good reading. Seems no one thinks I have an ignition problem. Remember, think I said, just a squirt of fuel into the carb and the engine starts. Does that say anything about a possible valve problem?
 

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Jerry, I too doubt its a broken valve spring, but It could sure be a bad head gasket, a burnt valve or carbon causing one to not seat properly. Before throwing parts at any engine I make sure what;s wrong and why. It's your money, go ahead and put a new carb on and maybe it'll solve all the problems. But then maybe not too. Then what? From my experiences, a carb doesn't usually perform perfectly and then all of a sudden quit working entirely. Usually there's a period of rough running beforehand. Perhaps something is plugging your fuel flow in the tank or before it gets to the carb? Maybe you got a slug of water in your fuel and thats whats in your carb now? It usually pays to check out whatever may cause an issue before adding parts is all I'm saying. Good luck!
 

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Not a bad idea to drain bowel and examine for water.That was another incident with same mower.Stored outside with tarp,water got into fuel gauge/fuel cap with lens missing.
 

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Discussion Starter #7
On fuel, that's the path I have been trouble shooting I checked fuel all the way to the carb, ie, know the fuel lump is working. But, I don't know the volume or pressure if important. I cranked the engine with the fuel line off the carb and caught I'll estimate 2 oz of gas from cranking the engine 5 seconds. I assume that's plenty of fuel and very little pressure is need to fill the float reservoir with gas. I also checked the solenoid off the engine and the wire from the ignition to the solenoid. All seems fine. Think tomorrow take the armature out of the solenoid to see if that corrects the problem, i.e., the solenoid hangs up when in the carb and doesn't pull down when the power is applied. In any case this will give the solenoid a full test.
 

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Yeah, water is heavier than gas and will not feed up through the passages in the carb. So if you had gotten some in your tank due to rain, your engine would start with what gas was in the carb, but as soon as that was used up and the water made its way to the carb it would be like shutting the key off.
 

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I had a briggs vtwin that I used pretty regular. I knew it was low on gas and finished off the last of a container into it. It started and quit after a few minutes. Same as you it would fire on carb cleaner. Soon as I started draining the fuel I saw the gas was bad. I concluded that rain may have got into my storage container. Fresh gas and she was good.
 

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"All of a sudden" type engine faults that are fuel related ... I'd look at junk in the fuel line, a sticky float, sticky needle, or a collection of crud that blocks the tank outlet on a whim, and then releases as the 'drain' action stops.
tom
 

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Discussion Starter #12
Nice there seems to be a consensus that I have a fuel problem, not a valve spring, head gasket,..... problem. Again:
Spraying carb cleaner into the carb (and all the exterior levers and springs) resulted in an immediate and easy start, only a few turns of the engine and it fires up, and quits when the spray is gone, maybe 2 seconds. Also, again, I have checked that fuel is being pumped into the carb by removing the line at the carb and pumping gas into a container by cranking the engine. I also removed the solenoid (anti-backfire) and checked that it operated and released first by connecting to battery, then by turning the ignition on/off. Of course this was done while the solenoid was operating in the resistance of the open air. Also, the solenoid is on the bottom of a single float tank which was drained by me first removing the solenoid and the cutoff chamber (name?) and off and the whole chamber/bowel came loose and any fuel or water therein ran out. Sorry I don't recall if there was much or any fuel running out but I think there was. In any case this allowed me to look and see the that the solenoid cutoff hole was open and clear. Thus, my plan to pull just the solenoid and removed the valve/plunger and putting it back on. This would in effect defeat the solenoid and clear it of any charges it is not operating correctly. If the problem continues my conclusion is the carb has internal problems and simply replacing the carb would fix the problem. Two unknowns: 1) is the fuel pump okay pumping an estimated pint per minute, at an unknown low pressure. 2) the float chamber just goes back on, there isn't a wrong way, I could not feel any detents or other position sensitive behavior when I put the chamber back on (is on bottom of carb and a feel for the right fit position) and screwing the solenoid back in to hold it altogether. The chamber is not a simple bowel, it has an offset shape.
 

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Discussion Starter #13
Update: removed solenoid (anti-backfire) and disassembled so I could remove the armature (part that moves up under spring and down under electromagnet when ignition is on). The bowel comes loose with this action so I carefully lowered and observed the bowel was full of gas. Fresh gas in the tank, only a few day old and with Stabilizer in gas. Reassembled and getting down on knees I could not see any specific rotational orientation needed other than for hose clearance below carb. Got back on tractor and after a few cycles to fill bowel the engine started but soon quit. I got off to look at carb and could see significant gas leakage due to need for new gaskets in the bowl and perhaps solenoid. I let gas dry and tried again, only briefly because of fuel leaks, and no sign of life, again gas was leaking. Fuel line and pump clearly working. As a minimum I need new gaskets, thus perhaps a rebuild kit would be the way to go, but I still like just replacing the carb. Now I have to make sure I order the correct carb. Welcome comments and correction to my way of approaching/thinking. Tips on model of carb and determining: look up in Sears parts (Craftsman GT3000) using model of tractor or looking for a model number on carb, if I can find it.
 

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You need 917.xxxxxx tractor model - GT3000 is not enough. Normally under seat. Google # and many sites come up selling parts. Pick one. Try to find engine model # in diagrams.
Or if you can find Kohler model # on the engine, google that. The carb # will be on the sites.
Doubtful the carb has a model # on it.
 

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You need 917.xxxxxx tractor model - GT3000 is not enough. Normally under seat..........
I list 4 GT 3000's in my homemade database. 1 Briggs & 2 different Kohler models. None of them 20 HP.

You can likely download an Owners Manual at-
searspartsdirect.com
Kohler Service & Owners manuals from the Kohler site.

Sounds like a clogged passage in the carb.
 

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Discussion Starter #17
Thanks for ideas on how to identify the correct carb. robhay2, similar looking carb but mine has a float bowl that is held only by the solenoid bolt body it has. The one pictured seems to have 4 screws holding each corner, looks better than what I have.

Tractor Craftsman 917.27306 Part number in the manual for a complete carb: 24-853-25 That I the sears po.
 

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Discussion Starter #18
Found carb on ebay for $47 delivered and can be delivered by August 27, shows USA flag, suppose that at least means shipped from a USA address. From Sear's manual engine is CV20S and carburetor is as already noted by me 25-853-25. The carb shown on ebay is a perfect match to what I recall the carb looking like, e.g. where throttle and choke wires connect, that's important.
 

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Discussion Starter #19
In case anyone is or later reads this far I give the following "learning" from my perspective. The problem was the anti backfire solenoid. Fixed as described, disabling the solenoid. I will likely leave it that way, not repair.
After tightening the solenoid nut (19 mm, sizable bolt threat) holding it and the float bowl to the car body the fuel leaking stopped. Tightened to an uncomfortable level to stop leak, the gasket was not replaced, more if anyone interested.

So I continued to test by mowing with frequent checks for leaks for about an hour. Mowing heavy grass and the engine seemed to perform as in the past. Fix done, subject to decision on a though to rebuild and thus replace all gaskets.


My shared learning: testing the solenoid is not sufficient if limited to, applying power to solenoid and observing the anti backfire retracts, and springs back when power removed. Checked both disconnected and using the battery directly and by using the ignition switch with the solenoid plugged back in. As already reported this did lead to a partial start, leading me to removing the actuator/armature that moves up and down under spring/power and reinstalled the thus disabled anti backfire case needed to reattach the float bowl.
 

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That's great,fixed for free.I tried to post about my solenoid incident,with the kohler,a few days ago,but no go. My Kohler sat for 10yrs,bought it,put gas in it,used it for six yrs.with no problems,till I ran out of gas.That must have loosened up, dried up gas, from sitting all those yrs.Looked like white glitter,must have settled into solenoid plunger and froze movement and burned it up.I removed pintle ,and it still never backfires.
 
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