Spark plugs

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doc308
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Spark plugs

#1

Post by doc308 » Sun Sep 27, 2009 5:34 pm

Can anyone give me a guide guide to spark plug brands/ranges that would work well for a'48 pan. For example, what Champion or NGK plugs correlate with #2 and #3 Harley plugs?



mbskeam
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Re: Spark plugs

#2

Post by mbskeam » Sun Sep 27, 2009 6:38 pm


doc308
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Re: Spark plugs

#3

Post by doc308 » Sun Sep 27, 2009 6:50 pm

Thanks for the general reference, but it doesn't address motorycles. I'm looking for some specifc recommendations from experienced riders as to what plugs to try in my '48 pan.

panhead
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Re: Spark plugs

#4

Post by panhead » Sun Sep 27, 2009 7:20 pm


FlatHeadSix
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Re: Spark plugs

#5

Post by FlatHeadSix » Sun Sep 27, 2009 10:05 pm

Doc
Here is a link to another neat cross-reference that you can download and keep in your references.

The current production NGKs don't seem to have a very good reputation in the vintage pans or flats, the reported failure rate is high compared to some of the other choices and they also appear to be resistor plugs in spite of what the sales reps say about them.

mike

viewtopic.php?f=65&t=5402&start=0

FlatHeadSix
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Re: Spark plugs

#6

Post by FlatHeadSix » Sun Sep 27, 2009 10:23 pm

Doc,
Here is a link to another discussion we had a while ago about plugs. As noted, the Champion J12YC is the exact same plug as the Harley-Davidson 3-4 plug that the dealerships are currently selling (at a little higher price because they say H-D on them), they come from the same production line at Champion with different markings on them.

Also note that if you are going to experiment with heat ranges that the numbering system is different for the various manufacturers. For Harley brand plugs lower numbers mean hotter plugs, just the opposite for the Champs. Also remember that heat range on a plug has nothing (or little) to do with how hot the engine runs, all it determines is how hot the PLUG runs.

mike

viewtopic.php?f=5&t=5397&p=20602&hilit= ... lug#p20602

john HD
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Re: Spark plugs

#7

Post by john HD » Sun Sep 27, 2009 10:59 pm

doc,

NGK B6L is a good plug for pans.

i only change mine when the outsides get rusty.

the spares i carry almost always are given to friends with starting problems.

avoid any resistor plugs, they will start and run but usually fail in short order.

john

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Re: Spark plugs

#8

Post by Bosheff » Sun Sep 27, 2009 11:04 pm

Go buy yerself (4) H-D 3-4 spark plugs. Put 2 in the engine and keep 2 for backup. If yer engine is reasonably close to stock, 4 spark plugs should last ya a good long while unless yer mill is tired or for any other reason deviates greatly from stock configuration. This takes the guesswork outa cross referencing and possibly causing unneeded engine damage or just plain poor performance in the future....bosheff

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Re: Spark plugs

#9

Post by 108 » Mon Sep 28, 2009 12:48 am

A Champion RL 95YC fits a '48 head correctly and I dont touch them all season with about 8o% suburban and 20% highway rideing. From what I've seen of Pans around here, carb tuning is usually the main reason for spark plug problems.

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