Spark plug assessment

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Jul 29, 2022 | 07:14 PM

#11

seniorsuperglideE8

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Joined: Jan 2007

Posts: 15,787

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From: along the shore of Mishigami

The spark plugs from Champion that are comparable to the HD 6R12's is the Champion RA8HC. Still gapped at .039"-.040 "

Last edited by seniorsuperglideE8; Jul 29, 2022 at 07:17 PM.

Jul 29, 2022 | 07:27 PM

#12

Rounders

Seasoned HDF Member

Joined: Mar 2021

Posts: 17,881

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From: backwoods

to really read plugs get it up to speed, and shut bike off. I've never actually done it, cause it is a nuicance.

Jul 30, 2022 | 07:10 AM

#13

Baird

Road Master

Joined: Jun 2013

Posts: 1,239

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From: St. Catharines, Ontario

If the the only thing you did was replace the plugs and now there's a fur coat on the new ones, the problem is the plugs. Assuming the old ones where ok looks wise.

Jul 31, 2022 | 10:14 PM

#14

baldric

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Joined: Jul 2008

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From: Edmonton

Aug 1, 2022 | 09:06 AM

#15

John CC

HDF Community Team

Joined: Aug 2018

Posts: 3,010

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From: New Hampsha

Oil fouled plugs will look like the picture above, wet and black. Plugs that have been running too rich will look more like they're coated with dry gray or black powder.

Quote:

Originally Posted by Rounders

to really read plugs get it up to speed, and shut bike off.

This is called a "plug chop" and is used to check main jet sizing, but isn't too useful for long term trend analysis.

Last edited by John CC; Aug 1, 2022 at 09:11 AM.