What causes plug damage?
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Road Master
Joined: Jul 2005
Posts: 1,081
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From: Central Ontario, Canada
What causes plug damage?
I've had my carb cleaned and a second set of plugs installed. (one plug in the first set was faulty)
I got about 80 miles of nice running and then the missing and backfiring started again. Mainly the back cylinder - left pipe.
Could a coil cause a plug to go bad?
Could the coil be bad?
Any thing else to look at?
Thanks
I got about 80 miles of nice running and then the missing and backfiring started again. Mainly the back cylinder - left pipe.
Could a coil cause a plug to go bad?
Could the coil be bad?
Any thing else to look at?
Thanks
RE: What causes plug damage?
The biggest contributor to plug damage is a lean running engine. You'll burn the little suckers right up. Running too rich will foul a plug and cause the missing and backfiring too. With a carb there is a really good chance you are running rich. If you had EFI I would say you are probably lean. How do your plugs look when you pull them?
Road Captain
Joined: Mar 2006
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RE: What causes plug damage?
KenM, what Terry 1955 said plus, If your plugs look ok with no visible damage, try switching plugs from front to rear cylinder. If your miss is on the front cylinder after switching plugs then you know its definately a bad plug. You could also have a bad plug wire that may be causing the plug to foul. Give us a bit more information. What year and model bike. Does the bike continue to miss on the rear cylinder after sitting and cooling off over night? I have seen a coil act up when it gets warm but will function normally when it has cooled off. Post back with some more info and we will try to help you............BG
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Road Master
Joined: Jul 2005
Posts: 1,081
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From: Central Ontario, Canada
RE: What causes plug damage?
ORIGINAL: BigGeorge
KenM, what Terry 1955 said plus, If your plugs look ok with no visible damage, try switching plugs from front to rear cylinder. If your miss is on the front cylinder after switching plugs then you know its definately a bad plug. You could also have a bad plug wire that may be causing the plug to foul. Give us a bit more information. What year and model bike. Does the bike continue to miss on the rear cylinder after sitting and cooling off over night? I have seen a coil act up when it gets warm but will function normally when it has cooled off. Post back with some more info and we will try to help you............BG
KenM, what Terry 1955 said plus, If your plugs look ok with no visible damage, try switching plugs from front to rear cylinder. If your miss is on the front cylinder after switching plugs then you know its definately a bad plug. You could also have a bad plug wire that may be causing the plug to foul. Give us a bit more information. What year and model bike. Does the bike continue to miss on the rear cylinder after sitting and cooling off over night? I have seen a coil act up when it gets warm but will function normally when it has cooled off. Post back with some more info and we will try to help you............BG
I haven't pulled the plugs yet but they have less than 100 miles on them.
1993 FLHT EVO
The bike acts up cold but ok when hot.
This is the second time it's happened. Cleaned the carb and new plugs. There was a bad plug so my guy replaced the plugs again. 100 miles and it's back to the missing and backfiring when cold.(actually don't know about running hot this time - I turned around and took the van)
Thanks
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Road Master
Joined: Jul 2005
Posts: 1,081
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From: Central Ontario, Canada
RE: What causes plug damage?
ORIGINAL: Terry1955
The biggest contributor to plug damage is a lean running engine. You'll burn the little suckers right up. Running too rich will foul a plug and cause the missing and backfiring too. With a carb there is a really good chance you are running rich. If you had EFI I would say you are probably lean. How do your plugs look when you pull them?
The biggest contributor to plug damage is a lean running engine. You'll burn the little suckers right up. Running too rich will foul a plug and cause the missing and backfiring too. With a carb there is a really good chance you are running rich. If you had EFI I would say you are probably lean. How do your plugs look when you pull them?
Pulled the plugs and they are very black - like the BBQ grill or soot in a chimney.
I tried to clean them up and put them back in.
Backfire central again. Just like a gun going off.
Thanks Terry - BG & Tripl8
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Road Captain
Joined: Oct 2005
Posts: 564
Likes: 1
From: Lynnwood WA.
RE: What causes plug damage?
You,re way rich...check the idle mixture, float, air filter element...did you rejet the scoot lately ??
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Road Master
Joined: Jul 2005
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From: Central Ontario, Canada
RE: What causes plug damage?
Re jetted last fall but not many miles on it since. Just talked to my wrench and he's going to look at the carb tomorrow.
He thinks loke you, either way rich or a Fu-kooked coil.
I'l let ya know what it is/was.
Thanks again
He thinks loke you, either way rich or a Fu-kooked coil.
I'l let ya know what it is/was.
Thanks again
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Thread Starter
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Road Master
Joined: Jul 2005
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From: Central Ontario, Canada
RE: What causes plug damage?
ORIGINAL: tripl8
Good Deal...let us know!
Good Deal...let us know!
Popped in a cheap set of Champion plugs and she fired up like a new one. I beileve I was choking too much and it is probably jetted to rich as well. Raining like hell here for the last two days so I haven't gone for a ride.
Maybe tomorrow.