So bout a month ago grandpa had a no start on his old 42" craftsman tractor. He tree a new battery in it but still no start. I went over to trouble shoot and found the starter solenoid to be bad. Put a new solenoid on it but prior to the new solenoid being installed I tried spinning it over by hand as the 30amp starter fuse was blown as well and it was almost locked up. I put some muscle into it and got it to turn over and as soon as I did gas POURED out the muffler. Checked oil and the case was completely filled with fuel. Pulled muffler off and got as much of the fuel I could out of it. Pulled the plug and drained all I could from combustion chamber. Plug looked good, like a finely roasted marshmallow. Drained the "oil" and pulled the carb off to clean it. The bowl had some rust in it but that was it. No gunk or jelly from bad gas. Figured maybe a piece of rust got caught between the needle and seat and since it's gravity fed it just filled the engine. Also made sure the gas tank vent wasn't clogged and it wasn't. Cleaned the carburetor up and reassembled everything, fresh oil and it fired right up and ran fine. Was smoking at first due to muffler not being completely dry but let it run for a little and smoke cleared up. Let it sit a few days then went to start it again and zero problems. No fuel in the oil and not smoking. He picked it up and ran it trouble Free for a few weeks then one day he took it out, fired up without any issues like normal, got to end of his driveway and engaged the PTO and started cutting and a few feet in the thing elegedly started smoking big time and was down on power. He shut it off and started it back up a few times with same results. Smoke and no power. So I picked it back up (I didn't even try to start it) now assuming it had a blown head gasket and I pushed it into my garage to troubleshoot and pulled the dip stick and sure enough was FILLED with fuel again. Pulled spark plug and buncha fuel came out and the plug was very black and oily now. Took the drain plug out and drained the "oil", took air filter and muffler off to let it air out. Let it air out a day then did a compression test. Got 120psi. Did a leak down test and my tester is definitely not the greatest but does an ok job. That being said it was the best leak down results I ever got on a machine with the thing. I forget the numbers it read, I believe I got a 60% loss but only place I heard air escaping was out the muffler at TDC so assuming the exhaust valve has some carbon build up. Pulled the dip stick and had very small amount of pressure coming from the crank case, could hardly hear it it was so faint. Nothing more than what I would expect to see get past the rings on a motor that tested at 120psi compression. So given those numbers and results I don't think it's a blown head gasket just yet. I put it all back together except I left the oil plug, dip stick, air cleaner, and spark plug out so it could further air out and let as much gas evaporate as possible and then let it sit about a week with the fuel line connected. Came back week later and it wasn't full...but had gas that wasn't in it a week ago inside the cylinder and case. At this point Im starting to to pull my hair out as to what's causing this. Pumped as much of the gas out of the cylinder and crank as I could and moved on to the carburetor. It has one of those electric fuel shut offs on the bottom of the carburetor that I tested and is working properly. Pulled carb off again and was spotless. This time I noticed the little throttle cable return spring (the one that goes from the carburetor to the sliding mechanism bolted to the motor that controls the choke/throttle, I'm assuming is just a fail safe in case the throttle cable breaks it pulls the throttle closed instead of having it run st whatever position it was in when it broke) but that spring wasn't attached to the carb, the hook that attaches itself to the carb was only half there so it could pop off easily if you hit a bump so I put a full bend back in the spring and reattached it. It's not popping off now. I put a fuel shut off valve on it right at the carburetor. I tested the valve and it worked and had the valve closed and reassembled everything minus the air filter. Once reassembled I turned valve on and let it sit for about 30 minutes. Came back and there wasn't a puddle of fuel in the carb air cleaner neck nor on the crank or combustion chamber. Threw some oil in it and took it outside to fire up and fired right up. No issues with throttle but didn't put it under any real load. Just reved it up while it sat in place. It was smoking but probably for the same reason it did before cause the muffler had oil and gas still inside it. Pulled it back in garage and shut it down and closed the fuel valve. Gonna let it sit over night and see what it does.
I just don't understand what I could be missing here.....
Could the electric fuel shut off on the bottom of the carb not be closing all the way?
Is the needle and seat actually bad and causing it to flood out? Logically this is what I'm pointing to but the fact that it's not consistent is what gets me. Sometimes it can go a few weeks without flooding then out of no where decided it's gonna flood this week. Sometimes it will sit a day or so after being aired out and then flood out. Just isn't consistent and that's the aggravating part because I can't even recreate the problem on command. It's only when IT wants to show itself.
I'm hoping I can just fix it with the fuel line shut off valve but guess I'll find out tomorrow if it will work...or maybe I won't find out until I get a phone call weeks from now saying it is filled with fuel again!!
What do you guys think about this fuel flooding? Ever seen this issue before? Also if anyone knows if the way I tested the needle and seat is an ok way to test them that be cool too!
If tomorrow comes with no fuel issues I'll move onto the headgasket diagnosis but based on how quickly it fired up today I don't think it's gotta blown head gasket.
Thanks for any help/input!
FYI the pics were taken before I put the fuel shut off valve in but I put it between the filter and the carb to minamize the amount of fuel that could enter the crank if it infact desides to fill up over night.
Here's the specs on the engine.
15hp Briggs and Stratton I/C Gold
Model: 28N707
Type: 0162 01
Code: 9506054B
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I just don't understand what I could be missing here.....
Could the electric fuel shut off on the bottom of the carb not be closing all the way?
Is the needle and seat actually bad and causing it to flood out? Logically this is what I'm pointing to but the fact that it's not consistent is what gets me. Sometimes it can go a few weeks without flooding then out of no where decided it's gonna flood this week. Sometimes it will sit a day or so after being aired out and then flood out. Just isn't consistent and that's the aggravating part because I can't even recreate the problem on command. It's only when IT wants to show itself.
I'm hoping I can just fix it with the fuel line shut off valve but guess I'll find out tomorrow if it will work...or maybe I won't find out until I get a phone call weeks from now saying it is filled with fuel again!!
What do you guys think about this fuel flooding? Ever seen this issue before? Also if anyone knows if the way I tested the needle and seat is an ok way to test them that be cool too!
If tomorrow comes with no fuel issues I'll move onto the headgasket diagnosis but based on how quickly it fired up today I don't think it's gotta blown head gasket.
Thanks for any help/input!
FYI the pics were taken before I put the fuel shut off valve in but I put it between the filter and the carb to minamize the amount of fuel that could enter the crank if it infact desides to fill up over night.
Here's the specs on the engine.
15hp Briggs and Stratton I/C Gold
Model: 28N707
Type: 0162 01
Code: 9506054B
