# Problem with B & S 15.5 hp 28u707 in Craftsman tractor



## Fortune50 (Aug 28, 2006)

My Dad's (2000 model?) Craftsman lawn tractor died on him the other day while mowing. The engine is a 28u707 model, 1174 type, 15.5 hp OHV. It started out of nowwhere as a sputter, then running again for few seconds, then dying as though it ran out of gas even though it's not empty in the tank. He says it will start up and run for an instant and then slow down & die as if it ran out of gas. Can that wire on the carb cause this problem, is that part of the choke system or some kind of antibackfire device? How does it work and what does it do? I've done the maintenance on it for him. This year in May I put on a new airfilter, fuel screen, spark plug, & oil change. Anyways would like some help diagnosing this for him as he's retired and on a fixed low income and I dont' live close (I'm not rich either, lol). I've had alot of experience with a 1974 Briggs 8hp engine in a rider I worked on while growing up. But this engine is a wee-bit different, lol...


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## peppy (Jul 19, 2006)

Not sure what wire you are talking about (picture?) But either way, it sounds like a fuel problem. One of two things I would look at since you already did a maintenance job on it is to take a look at the fuel line and see if there is any holes in it. Also, if fuel has been sitting a while. It can build up varnish and eventualy clog up the carb.


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## kbalona (Apr 27, 2006)

That wire that goes to the bottom of the carb is for the fuel shutoff solenoid. Normally if that is bad, it will not run at all. To check if it is opening and closing, put the park brake on, put your ear close to the carburetor and turn the switch on, then off. You should hear a click when the switch goes on, and another click when it goes off. 

Also could be some water in the carb...some dirt in the carb. Check to see if it has a spark.


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## Fortune50 (Aug 28, 2006)

Thanks for the replies guys! I'll get back to you guys if I find out anything new. BTW the local shop charges $55/hr. labor, $35 to pick up & bring back the lawn tractor (6 miles each way), and about an hour to rebuild the carb, so about $55 to rebuild it plus parts, does that sound about right?


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## bugman (Aug 12, 2004)

DIY it and be out under $20......
Have you tried it without the gascap?


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## Fortune50 (Aug 28, 2006)

bugman said:


> DIY it and be out under $20......
> Have you tried it without the gascap?


I dont' live closeby (about 290 miles away roundtrip). He did say he added fuel to the tank to see if it would keep running, it did not, so the gascap was removed. Someone mentioned to me that the solenoid can be removed and a 1/4" bolt put in its place and then start the engine to see if it'll keep running, sound like a good idea?


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## kbalona (Apr 27, 2006)

um, not sure about that. I've heard that also...at least for temporary. Not sure if it'll work tho. If you want to eliminate the solenoid (fuel), remove it, attach the wire, and turn the key on/off. the little rod on top should go in and out, in when key is on and out when key is off. Make sure its not sticking up or down. It should work properly every time.


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## Fortune50 (Aug 28, 2006)

To update this thread, I got my dad's mower running. It was the anti-afterfire solenoid, the local shop recommended just replacing it with a bowl nut & washer, $32 cheaper. Now that I've thought more about it, I want to install a fuel shut off valve in the fuel line to avoid any potential problems with the carb flooding the crankcase w/ gas or gumming up while the mower sits over the winter since the fuel flow is a gravity feed design...


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## 30yearTech (Sep 14, 2006)

It's a good idea to have an inline fuel shut off valve to prevent the possiblilty of oil contamination if the carburetor floods, however if your doing it just because you removed the solenoid you don't have to worry about it. If the carburetor floods even with the fuel solenoid, gas will flow through the carburetor and can fill the crankcase, I have seen this dozens of time on units with the solenoids. Installing an inline fuel shut off will prevent this as long as you remember to shut off the fuel.


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## Fortune50 (Aug 28, 2006)

Thought I'd update this thread and let everyone know that the mower's running fine, but pops after shutting it down after use. Is this going to be something that can cause a big problem, or is it not a big deal?


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## hdman97 (May 25, 2006)

have dad be sure to turn down throtle all the way before turning off key


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## bugman (Aug 12, 2004)

Yes turn it down to idle, let it set like that a couple seconds and shut it off...... its nothing to worry about.


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