18hp GX610 has weak spark

[Cody]

<font color=e87400>Hi.

I have a Honda 18hp GX610 I recently bought. It supposedly has low hours. It's pretty clean thus probably true.

I received the machine via UPS & it has a little damage on it, seller says it happened in shipping. I never saw a picture of it to verify it's actual condition thus the seller could be yankin my chain & has dumped a problem child on me.

Anyway, the machine has weak spark on the left side & I can't figure out why. My mechanical expertise is limited. I'm using one of those little inline spark testers that lights up. It lights up very weakly on the left side. But very bright on the right. <i>The shipping damage is little more than a cracked plastic front motor cover & a dented recoil cover & muffler guard but that damage is on the LEFT side. Just FYI</i>


<li>I change the spark plugs around & still a weak spark.
<li>I took the coil off (whole assembly, wire boot & all)& tried on one of my other GX610 motors & it produced good spark.
<li>I took a good spark coil off another GX610 motor & put it on the new motor & it produced a weak spark.
<li>Also, just to be sure, I tested the Inline spark tester on other machines & it's bright on all heads.

So what can cause a coil to have a weak spark on a motor aside from the coil, wire or plug? The right side coil lights up strong & the left lights weakly. I've ruled out the spark plug, & the coil. I also tried it with the flat plug wire on the coil disconnected & got the same results<i>(I believe the flat plug wire is a ground wire for the kill switch. Is this right?)</i>

Any ideas would be helpful.

Thanks
Cody
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[Larry L.]

Have checked the valves on that side?,could need setting

 

[Cody]

<font color=e87400>Hiya Larry.

Hmm That's pretty much out of my realm of experience, I don't know how to check them. Is it something you can explain simply?

How do the valves factor into the spark & if they are out of adjustment is this something that could have happened from the left side impact?

Thanks</font>

 

[Larry L.]

could have happened from the left side impact?

No

Cody I do not know the settings for the valves,I do it by ear.

Like opening and closeing a door is how they work,a lose door will cause a weak spark even the motor will sound weak when the valves are out of justment.Everything has to be in time to set them right,meaning the spark has to be at a set point before you begin to to set them.

Someone in front of the bar could explain it to you

Have you tryed the internet,small engine forums,hoddy talk is one.

 

[Mark]

Might be a bad diode!

 

[Cody]

<font color=e87400>Ok, Well where's the diode, what's it look like & is there one for each side or...

I see there's a little black box about 1 x 1 x 3/4, has 3 wires, One i assumed was to a gound kill-switch. The other 2 go to the coils. Is this it?

Thanks</font>