# bouncing on the governor @ low speed



## Oldphil (Dec 7, 2010)

Yesterday I was called by a buddy with a very bad surging issue at low speed, he has a 10 year old Honda a pretty big rubber track job. We went through every last thing, cleaned the carb reset the governor. THe setup for the governor was wrong in the manual but that was easily figured out! We were still scratching our heads when I thought of the one thing we din not check idle speed, it was bouncing so badly who would have thought!!!!!!!!!! Over time the plastic screw had worked its way out, a few turns of the screw driver and it purred like a kitten. As usual one cannot see the forest for the trees, I have been a mechanic for near 50 years and let something that simple get to me. Moral if your machine starts to surge check the idle first, all the governor sees is the speed getting to low and it responds by bouncing the RPM up and down.


Phil


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## bwdbrn1 (Nov 24, 2010)

Thanks for pointing that out Oldphil. Like you said, sometimes we can't see the forest for the trees, and we over analyze.


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## yosfam (Apr 22, 2012)

Just bought a used 3-5 year old hs724ta. The engine surges at low all the way up to high speed. I called the person that sold it to me and he recommended to change the gas .It has been sitting in the unit for over a year. its funny ,when i revved the engine and went into the choke and back to low speed theidol leveled .I shut it off and then started it again and it started surging again. ANY IDEAS?


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## bwdbrn1 (Nov 24, 2010)

Hi yosfam, welcome to the forum. If the gas had been left sitting in it for as long as you say, there is a good chance that it has gummed up the internal works of the carb. As was already recommended, drain the old gas out of the tank and replace it with new. When you get the new gas, add some fuel stabilizer like Stabil or Seafoam treatment to it as recommended on the product label. If you're not familiar with them, these stabilizers will help keep the gas from going bad, as Stabil claims, for up to a year, and lessen the chance of gumming up your carb. Since it does run, you might try removing the cover over the carb, and if possible, dribble a bit of Seafoam directly into the carb barrel. Just a dribble, not a splash. It will spit and sputter a bit in protest, but should smooth back out and hopefully this will clear the goop out of the carb so you don't have to take the carb off for a cleaning.


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## JamesReady (Mar 5, 2012)

Yosfam.... I just went through this issue with my HS1132.... She was surging like crazy and backfiring when not under load.....

The cause was a blocked idle jet.... It's the easiest thing to fix that I've even seen.... Here you go....(I hope you have a similar carb)...

Remove the black plastic idle screw......then remove the black piece of plastic sitting just underneath it.....Now you are looking at another black plactic thing (idle jet)...just pull it straight up with a pair of needle nose pliers....(It's held in with a tight fitting "O" ring.... At the bottom of this piece you'll see that there is a hole (2mm?) horizontally.....but in the bottom there is a VERY FINE hole that runs vertically to this other hole.... That's where they plug....I had to use a magnifying glass to see this little hole.....

I snipped off 1 small brass wire from a small wire brush and with it in the needle nose pliers, I was able to push it through and dislodge the piece of crap....

She runs like new again....

This piece of crap was SOOOO small that I could hardly see it man....

Highly recommend always using a funnel with a fine filter when fueling up the blower....the crap comes from the gas tank.....

Hope this helps you or someone else man...

Toodles....James


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## Wanderman (Feb 13, 2018)

JamesReady, you be the man! I had same symptoms with my HS1132, also a 2007 model. And it was fixed in the same way as yours: removing pilot jet and cleaning it out. After ten years of use my gas tank had accumulated some fine sediment. I made the error of running the machine out of fuel, which may have concentrated the debris and swept it into the carb. Alternatively, because the sediment bowl on the carb is supposed to catch that debris, there is another possible cause of the pilot jet problem: the o-ring that seals it into place. I noticed it had frayed edges where it was pressed flat along the bore. A bit of that rubber had worked itself up and into the 2mm bore that the pilot jet feeds into. Replacing that o-ring every few hundred hours might be a good idea, before it has worn to the point of fraying.


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## tadawson (Jan 3, 2018)

I have an older Honda mower that did that, but the pilot refused to be cleaned (could pass wire, whatever, and no improvement). I think that with age and fuel, the plastic may deteriorate and the orifice shrink. I just had a lean surge (idle was OK) and ultimately replaced the pilot jet to resolve the issue.


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## Wanderman (Feb 13, 2018)

Well there you go: a pilot jet issue. I've known plastics to swell after long-time exposure to gasoline. The plastic around that jet bore could have swelled to choke the passageway. I edited my response above to add my observation of the o-ring fraying and partially blocking the 2mm passageway that the pilot jet empties into.


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