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Have a Honda 8D that drops a cylinder at idle.

J

jgmo

Outstanding Contributor
Hi,
Simply comparing the looks of the plugs might give some info.

If you haven't put new ones in for a while you might want to do that at least swapping in a set of "spares" you may have saved. I recommend using NGK only.

I think checking the valve clearances and compression might be the next logical step if new plugs doesn't help.

If you remove the valve cover, make sure to clean out any sludge in it especially in and around the crankcase breather baffle. Check the breather hose and make sure it's clear. If the outboard sits alot, critters build nests in places like that and I think excess crankcase pressure might cause a misfire condition like this.

Good luck and please post how you make out.
 
T

Tiki91

New member
the funny thing is it was running perfect in a barrel at home .sold it to a gentleman and he took it home put it on his boat and it started running this way.all within a day.I am at A loss he is bringing to me to have a look at.will swap the plugs and let you know.the fella I sold it to does not know how to change spark plugs LOL.
 
J

jgmo

Outstanding Contributor
Yeah....not surprising...

...I think a large portion of the population can't change a spark plug anymore.

As my sweet ol' grandma used to say...."oh my goodness!"

I wonder if he turned the idle way down???
 
T

Tiki91

New member
jgmo said:
Yeah....not surprising...

...I think a large portion of the population can't change a spark plug anymore.

As my sweet ol' grandma used to say...."oh my goodness!"

I wonder if he turned the idle way down???
Click to expand...
Did you see the video I posted?
 
J

jgmo

Outstanding Contributor
Yes, I watched the video and it does seem like it may be dropping a cylinder. I would want to pull the plug wires while thats happening to find out which one it might be.

But hey, it could be something going on with the kill switch or another wire connection due to vibration for all I know.

I've had ignition coils cause some strange running issues before.

When you replace the plugs, look carefully inside the plug wire boot for signs of corrosion and smear a bit of dielectric grease inside the boot before putting back on the plug.
 
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