# HSSK50 is hunting



## Dave C (Jan 26, 2015)

So, after servicing the exhaust valve on my 5 hp Craftsman blower it starts and runs but oscillates (hunts) especially at idle. If I screw the idle mixture adjuster in I can get it to almost be stable, but it's nearly closed at that point and going further will stall the motor.

The carb is new, bought in November, and has less than 5 hrs on it. I've sprayed carb cleaner in the idle mix screw hole with no effect.

It didn't do this before the engine service, and I've checked that the intake manifold and carb are tight. Gaskets are new.

Under load the machine runs stronger than it has in years. If I can correct this problem, it'd be like a new machine.

Where should I be looking?

TIA


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## classiccat (Mar 1, 2014)

so it hunts at both idle (low-speed) & high-speed / no-load?

Have you tried going the other direction with the idle jet? Starting at 1-1/4 and trying 1-3/8, 1-1/2, etc?


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## Dave C (Jan 26, 2015)

Yes to both questions. No load high speed is a quick cycle, idle is much slower.


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## Toro-8-2-4 (Dec 28, 2013)

The only thing I can think of that that may effect idle after a valve service would be the head gasket or intake gasket leaking.
Try spraying some carb cleaner around these areas to see if it effects idle. If so it would suggest a leak.

But is sounds more like the idle circuit is dirty.

Did you soak the carb over night in carb cleaner and blow out with compressed air?


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## motorhead64 (Dec 15, 2013)

If you have a hunting engine at wide open throttle and no load, you have a carb issue or your governor linkage is improperly attached. MH
http://www.asos1.com/tecumseh4hp/Tecumseh.pdf


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## classiccat (Mar 1, 2014)

This is a tricky one....smells a little different than the normal idle-circuit issue...many people either set their idle jet too lean...or the idle circuit is restricted from fuel storage, improper cleaning, dirty fuel system, etc.

What you're describing is a rich condition suggesting an air bleed restriction (air ports in the venturi) or a leak at the intake manifold. It's a new carb so the throttle shaft shouldn't be leaking. 

The L-head troubleshooting guide, indicates that incorrect float height could also cause a hunting/erratic idle.

...Or you bought the wrong carb for your engine.


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## RedOctobyr (Mar 2, 2014)

Like motorhead64 said, are you sure your governor and throttle linkages are connected properly, or at least the same as they were before? 

I just deliberately changed a link position on my governor, and that apparently introduced some surging. I'm going to put it back when I get a chance, and see if the surging goes away, but it's really the only change I made (no engine internals, or mixtures, were touched).


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## York v45 (Dec 27, 2014)

To confirm what others have said. I've had this problem when I messed with the throttle/governor linkage on my HSK50. I just put it back in it's original position as best I could and the problem went away.


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## classiccat (Mar 1, 2014)

the OP's problem exists at idle when the governor shouldn't be engaged; the throttle shaft spring swings the butterfly closed. 

Dave C, please confirm that you're getting surge when the throttle butterfly is resting (and not moving from) the idle-speed screw...when the motor is warm.

I wouldn't go mucking with the governor until you get that idle condition fixed; odds are that the high-speed / no load condition will disappear once you correct it.


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## motorhead64 (Dec 15, 2013)

The governor rarely needs adjustment unless it's been tampered with....but the links can easily be misconnected. The manual shows the proper link attachments for all Tec engines. If they are not put back correctly, they will not perform correctly. That being said, I'd still be looking at the carb as the culprit. MH


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## Dave C (Jan 26, 2015)

Thanks for the suggestions, guys. I'll try to narrow it down a bit -

The surging is both high speed with no load and idle. Under load the machine has really good power. Governor linkages are as they have always been. I mark the holes with a sharpie before disassembly. Governor arm has never been touched.

With the idle air screw in the nominal 1 turn out position the linkage will touch the idle speed screw when the governor swings that way. Low speed hunting is about a second cycle time, high speed is a bit quicker. High speed will drop to the point where I think the engine will stall.

Screwing the idle air almost all the way in cures the hunting about 80%. The machine is usable, but I'm an anal type and this annoys me.

The intake manifold was off and the carb was dry for about a week while I dealt with the exhaust valve and a couple other issues. Intake gasket is new and I used copper spray on it. Carb was not removed from the intake. The head gasket has been retorqued.

The blower is at my brother's house now (his POS is broken again). I told him to put some SeaFoam in the tank and spray carb cleaner around the intake - we'll see how it goes.


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