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Discussion Starter · #1 ·
I have a tractor with a 17 HP OHV 311777. Runs perfect, no noise, starts runs smooth. If it idles for a little while it smokes, but not white, so I'm thinking the carb may be out of adjustment, but there really isn't any adjustment on it is there? It runs perfect at full throttle.

Suggestions?
 

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Discussion Starter · #2 ·
One more thing. I just took another look at it to make sure everything was hooked up right and the spring that goes under the small rod from the carb to the governor lever wasn't connected, would that have any effect on this? Could that cause a rich condition at idle??

I don't think so, but too late right now to start it up and let it idle for awhile.
 

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kevin, 3 things, check air cleaner, over full of oil, head gasket gettin ready to blow, just a few thing it could be, tom
 

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If the items declid mentioned aren't the fix you might try running some "Seafoam" through it to clean out the "non adjustable" jets in the carb. Alternately, you could pull the carb and soak it in carb cleaner to accomplish the same result.

Ev
 

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Discussion Starter · #5 ·
I've had others with bad head gaskets and they smoked at full throttle and burned oil. It's not like that, seems like its getting too much gas only at idle. Any chance it could be old gas or that spring? I'm going to run it for a long time with seafoam in the gas tomorrow, but was hoping someone had this same issue and had a simple resolution. The filter looks clean, but I guess I could try that too. Wouldn't that keep it rich at full throttle too?
 

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That spring you refer to only keeps the slack out of the governor rod for smoother running, will not cause the symptoms you describe. I would be very surprised if there is not a low speed mixture screw with a "limiter" cap on it on the left side of the carb when looking at intake end.

Walt Conner
 

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Discussion Starter · #7 ·
oh, yes there is that low speed limiter cap, would turning that help this, should I pull the limiter cap off so that I can turn it more, counter clockwise to allow more air or is this a fuel one so clockwise?
 

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Worn valve guides or stems will also allow oil to be sucked in from the crankcase at idle and cause smoking..the amount of vacuum at the guides is greatest at idle,so that is when more oil will be sucked in and burned..at higher rpm's the vacuum drops and the smoking may decrease or stop altogether....
I've had to replace valve stem seals on dozens of small block Chevy's to stop them from smoking at idle..I dont think small engines use any valve stem seals though,at least not the older flatheads I'm familiar with anyway..
 

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Discussion Starter · #11 ·
before i start taking things apart. could a bad valve stem seal cause this? could dirty or misadjusted valves cause this and could it just be the headgasket? I don't want to tear things apart for nothing, but I just don't see this as being any of those.
 

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Discussion Starter · #13 ·
Well guys, sorry to waste your time. Tried another carb, waste of time. I pulled the head, head gasket cooked. Not sure why it wasn't bellowing smoke wide open and fine full throttle, but, it had two huge wide gaps in it, but either way it is resolved and will be fixed and running perfect shortly. Thanks for your answers
 

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ok. i read all the old threads and did a ton of other research. original problem was oil coming thru muffler and smoking off. after research, i pulled the breather and replaced the gasket under there. same thing happenes. then i put a new head gasket in. same thing. maybe even a little worse. i should note that other than the oil and smoke it runs great. good compression etc....after working on it, it runs good for 30 seconds and then the oil returns. i'm open to suggestions. i'm close to giving up and junking it-dave in ohio
 
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