I have a Huskee push mower with the Kohler xt650 engine on it. It sat for a year with untreated fuel in it (death in the family I didn't do my chores). I went to start it and it was low power. I cleaned the carb and a new plug. I also installed a new ignition because the plug wire was getting crispy against the exhaust. It runs well without the air cleaner in but bogs down when I put it in (also new). Because of the oil marks on the cleaner I took it apart and cleaned the pcv. Same problem. I noticed today that the carb is blowing not oil but fuel out of it as it runs. Literally with the filter off there is a mist of unburnt fuel that blows out of the carb. thinking maybe bad rings and it was raw oil I took the pcv arm off and even more blew out the unrestricted carb hole. I put my hand in front of the hole in the carb and was able to literally get gas dripping off my hand. Knowing how engines work I am guessing the intake valve isn't closing but I have never seen this before. Can anyone point me in the right direction on this? If it is what I'm guessing how do I fix it? If I am just dumb let me know that too and why. Thanks in advance for the help, I just hope someone can solve this for me before I go buy yet another mower.
Gas blowing out carb
- Thread starter zakdtv
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bertsmobile1
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Yes, or the exhaust is not opening
Slip the rocker cover off and have a look
Slip the rocker cover off and have a look
VegetiveSteam
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Yep. I would agree. A restriction in the muffler could definitely cause your scenario.
Well, I figured I would pop in with an update to my situation.
There was a bent pushrod. Now the question I have is why? The key looked fine for the flywheel so I dont imagine it was a hard stop. Also it still started and ran fairly easily and I cant imagine that kind of bend being able to move up and down... I dont know. My concern is if there is this much damage here is it worth it to keep buying parts or call it quits and get a new mower.
There was a bent pushrod. Now the question I have is why? The key looked fine for the flywheel so I dont imagine it was a hard stop. Also it still started and ran fairly easily and I cant imagine that kind of bend being able to move up and down... I dont know. My concern is if there is this much damage here is it worth it to keep buying parts or call it quits and get a new mower.
bertsmobile1
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The pushrod bends because the cam tries to push it and the valve does not move
With that amount of wear it was due for a replacement in any case
I always fit two steel ones ( exhaust ones ) when the alloy wears thin
You can slip the steel one in there, adjust the lash & try to turn the engine over by hand
Most likely the inlet will not move
Usually a gentle tap on the end with a small hammer. or hammer & small punch will free it up if it is just a bit of rust from sitting too long
The valves & valve guides are identical dimensions so the inlet & exhaust guides should protrude the exact same amount into the rocker cavity
If not then the guide has sliped due to overheating in the past .
With that amount of wear it was due for a replacement in any case
I always fit two steel ones ( exhaust ones ) when the alloy wears thin
You can slip the steel one in there, adjust the lash & try to turn the engine over by hand
Most likely the inlet will not move
Usually a gentle tap on the end with a small hammer. or hammer & small punch will free it up if it is just a bit of rust from sitting too long
The valves & valve guides are identical dimensions so the inlet & exhaust guides should protrude the exact same amount into the rocker cavity
If not then the guide has sliped due to overheating in the past .
Are the intake push rods aluminum in these? If so I would install the OEM aluminum push rod on the IN side. Makes it a softer sacrificial part just as Briggs does.
To me, overheating caused this. Course all the other issues can stick a valve per say. Rocker arm moved from its position tweaking the angle on the push rod.
To me, overheating caused this. Course all the other issues can stick a valve per say. Rocker arm moved from its position tweaking the angle on the push rod.
bertsmobile1
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Usually you flip the pushrod at major services to spread the wear out at each end.
Having said that I have pulled some engines apart and the pushrod had a wear hole in it
Sure sign that the oil was never changed .
Having said that I have pulled some engines apart and the pushrod had a wear hole in it
Sure sign that the oil was never changed .
Thanks for all the help. I figured I would pop in and give a final update. I got the new pushrods from Kohler. They came as 2 for a quantity and as far as I can tell the exhaust and intake were the same materials. I got it put together and it ran better but not great. Looking in the exhaust noticed it was getting gummed up so I drilled it and cleaned the spark arrestor. Put some putty on the hole and now it starts and runs like new. Thanks again.