# GX390 sputters when opening governor



## legarem (Sep 9, 2017)

Hi

I have a Honda GX390 recently fitted on my snowblower, Il works well but when I push the governor to raise the motor speed, it sputters and doesn't want to raise revolution. I tried the same thing with the choke partially closed to look if it's due to lean condition and it is doing the same thing. I cleaned the carburetor and it didn't help. I begin to suspect a bad spark plug or an ignition problem. Any idea about this problem ?

Thanks a lot


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## legarem (Sep 9, 2017)

I replaced the spark plug and also replaced the resistor in the spark plug cap with a metal part. Same sputtering problem when I open the governor to rev the motor.


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## RedOctobyr (Mar 2, 2014)

It's not terribly clever, but it's at least easy to try: something I've done when I'm concerned about a weak spark is to close the spark plug's gap down somewhat. That should make it easier for the spark to jump. The spark will be smaller, but if the ignition is weak, it might give it a better chance at actually creating a spark. And I figure a too-small spark is better than none at all.


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## legarem (Sep 9, 2017)

Spark appears good. How to be sure if it's a carburator or a spark problem ?

I used the snowblower today and everything works ok. Motor is smooth, it idles correctly but there is still this problem. I can go in 3 with full bucket of snow and the motor doesn't seem to lack power. The big question is: Do I really have the real power of this motor with this kind of problem ?


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## RedOctobyr (Mar 2, 2014)

If you have an inline spark tester (I got mine at Harbor Freight), you might be able to use that to monitor whether you're getting spark, while it's running. 

If it's clearing well, that's good. But as long as you aren't over-revving it (that is, don't push the governor open when it's already at full-speed), I don't think it should be stumbling/hesitating as you add throttle. That doesn't sound right. 

What does it do if you simply raise the throttle lever on the controls from low or mid, to high? Rather than messing with the governor itself, directly.


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## legarem (Sep 9, 2017)

RedOctobyr said:


> What does it do if you simply raise the throttle lever on the controls from low or mid, to high? Rather than messing with the governor itself, directly.


When I raise the throttle lever control, motor revolution raise freely wihout any hesitation.


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## leonz (Dec 12, 2014)

Are you saying the spark plug connector was bad and you put a scrap piece of metal in it to close the gap?? 

You may just need a new plug, be sure to gap the new one at 25 thousandths and make sure you have treated fuel. 
Can you heat up the snow blower before using it? If you had a bad coil it would die when the engine is 
running and hot no matter what the season is. 


?????


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## legarem (Sep 9, 2017)

No

The standard Honda spark plug cap has a 6 kohms resistor inside it. You can unscrew the spark plug clip inside the spark plug cap to replace the 6 k resistor with a metal part to lower the resistance to 0 ohms. As the BPR6ES spark plug has an internal resistor inside it against radio interference, the spark plug cap doesn't need 6 kohms resistor inside it. Doing that didn't change the situation.

I replaced the spark plug and gapped it to correct spec. It didn't change anything.

What do you mean by treated fuel ? 

No I can't keep the snowblower in a warm place.


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## jtclays (Sep 24, 2010)

legarem said:


> when i raise the throttle lever control, motor revolution raise freely wihout any hesitation.


147


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## legarem (Sep 9, 2017)

Great

So everything is normal with this Honda engine.
It doesn't bog on deep snow.

Normally, during summer, when I open governor on a B&S or a Tecumseh, they rev freely. Tecumseh with frozen governors sometimes revs so much they tend to go to self destruction because they rev too high.. I thought it was the same with Hondas.


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