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Intermittent Miss

M

mgssrs

New member
I have a 2018 Honda BF75D with an intermittent miss mostly at low and mid speed. It seems to get better after I run it wide open for a while then slow down. It still has warranty but I would have to borrow a trailer to take it to a dealer for who knows how long. Then I'm worried they'll say they can't duplicate the problem.

I replaced the ZFR6K-9E plugs with IZFR6K-11E and adjusted the valves before this started. It has new fresh premium nonoxygen gas and no fault codes. I would appreciate any help I can get.

Thanks
 
A faulty spark plug can give an intermittent missfire. Since the problem started after renewing the spark plugs, it is possible one is faulty. One may have been dropped & damaged before you purchased them.

Bob
 
bobmech said:
A faulty spark plug can give an intermittent missfire. Since the problem started after renewing the spark plugs, it is possible one is faulty. One may have been dropped & damaged before you purchased them.

Bob
Click to expand...

That was my first thought too. I put the old ones back in because they looked good and it still did it. So now I have the Iridium plugs back in it. I keep going back to the plugs or the coil. One plug looked slightly wet when I pulled them so I switched it to another hoes and put that coil at a different hole. Now that I have run it for a while I will pull them out again and recheck them.

I may just order another set of plugs but I don't want to replace $60 worth of plugs again if thats not it.

Thanks.
 
A couple of questions.

What prompted you to go with the iridium plugs?

And, did you use dielectric grease to reseal the plug boots?

I too am interested in what you find when you check out that one cylinder.

Good luck.
 
I switch to Iridium because they were listed in the owners manual and are supposed to be better. I'd go back to the original bit they are kinda hard to find now and cost about as much.
I did not use new dielectric bit will give that a try.
Thanks.
 
Well the miss seems to be gone but I'm not sure what did it. I replaced the fuel filter, and switched the plugs back to the original V grove plugs. I also readjusted the valves. I had adjusted the valves before this all started and rechecked them when this problem started. I checked them again now and they were all to tight. I don't know how but I am guessing I had used the wrong settings before. Hopefully this is the end of it.
Thanks for your replies.
 
Well, even though it's always satisfying to know what exactly was causing the issue it's still a WIN if she runs good and you're happy with it.

It's a flippin' machine and, who knows, it could have been a speck of dirt in an injector tip or a bit of carbon disrupting the combustion or.....something;>)

The great thing is you corrected the tight valve setting. THAT could have caused you some real headache down the way.

Goodonya!
 
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