What spark plugs do you use in your ironhead? Mine came with S/E SplitFires. I would like an alternative.

Anyone using NGK? Which one? Champion? Which One? Others?

I found an ngk plug fer an ironhead. (B6L) NOTHING SE is made for ironheads. If you look up the spec's for the correct plugs for our bikes and compare them to the plugs you are using, (S.E. splitfires), I think you will find your plugs are a little long. They don't hit the piston or anything but should be removed often so deposits don't build up on the threads exposed inside the cylinder which will destroy the threads in the head during eventual removal. NGK#B6L, Splitfire# SM21F,Autolite #216. Go to www.sparkplugs.com. They have application data for all types of plugs and also they have an application page for any plug type that will tell you what kind of CAR it's used in. Ever try to get a bike part at autozone? For instance,the plug for a '68 jeep p/u with a 327 will fit!

CRAP! I forgot! Not all Irons are alike. The numbers are different for a 1980. It says your plug reach is 1/2 inch whereas mine is 7/16"... S.E.'s will fit yours fine. You'll have to look up all those numbers agin' Sorry!

Hey Dabronco,

Thanx for the excellent website reference!

No problem at all. When you're cheap like me, you'll search all over the place to get what you need without paying for the Harley name!

I use Accel and Champions in my 74 XLCH......The Champions foul sometime, but I've never fouled the Accels. I actually use Accels from a Shovelhead. Don't ask me which ones, cause I can't remember and can't get outside to the bike right now. I'll get back to you on the size/number tomorrow night.

Accel U Groove In My 75

I used to use Autolite but I to bought a set of the Accel U Groove last year and they seem to work well, I've put over 4000 miles on them so far.

I've been using the Champion Gold plugs that Harley sells. They perform better and last much longer than the standard Champion 4R5. Harley calls them a 4R5G, and they carry the HD part number 32366-04. I like them better than Splitfires, too. I've used these for the past 4 or 5 years and have been very happy with them.

champions have done me well in my 74. I really don't like them in my hot rod but the ironhead seems to love them!

I have used Champions. Accel, Autolite, NKG Bosch Platinum, Splitfire.. what I have found that many times I was trying to use a plug to solve a carb or timing problem and once those issues were fixed the Champion plugs always worked well... even in modeling we experiment with hot vs cold glow plugs.. compression and fuel make up can vary, thus finding a plug that won't "flame out" becomes a never ending quest...

A lot has changed ....

Harley Davidson Motorcycle Genuine OEM Original - Panhead #4 Spark Plugs. Part # 32301-47
http://www.harborvintage.com/ebay/11/6797.jpg

Jim

Ive had good luck with NGK BPR6HS plugs in my '81

Just thought Id add some other plugs that would work
Champion RL82YC
Autolite 4123
H-D 4R5
Bosch W5AC

...They work GREAT with the Dyna S single-fire and my S&S E carb.

Autolite 216

Autolite 4316's run great in mine...........here is the address: http://www.autolitesparkplugs.com/results_fitment.asp?pid=4316

I like Autolites.

I use champions. They also make H-D's plugs. I have used others, but never noticed any difference.

I just replaced some SE branded Splitfires in my 82 project. They kept fouling. I've found Splitfires to be lousy plugs in other old vehicles.

A search of local autoparts stores was looking fruitless until I found a place that had Autolite 4123s in stock. $7 and change for a box of 4. While I can offer no real endorsement of these the bike does now at least start every time.....

BTW the new Champion number is 814.

I got those with the iridium center electrode and was kinda bummed about the price. But, I put those with a new battery in and I didn't even get to the bottom of the kick! Man, that bitch just WANTED to run!!! Kinda startled me, but a nice pleasant suprise! I'm also running a Dyna S single fire, don't know if that made any diff or not. Hey, I like them!

Dirty Dee

my 77 came with Autolight platinum MP 4316

...any suggestions for Magneto-Sportys?
Mine is pretty sensitive for city traffic (plugs become black more and more) and it results to hard starting next cold morning.

Thanx,
Andreas

...any suggestions for Magneto-Sportys?
Mine is pretty sensitive for city traffic (plugs become black more and more) and it results to hard starting next cold morning.


IMO that's common with magneto Ironheads. If you're spending a lot of time at traffic lights etc the magneto doesn't put out a very hot spark at idle and the plugs will do that. (carbon up from weak spark.) If your air cleaner is clean, the air/fuel mixture screw is set correctly, and the carb is jetted correctly; Make sure you're using non-resistor plugs and wires. Some people like NGKs. I like Autolite 4316 or Champion H8C. Also make sure your spark plug electrodes are carefully aligned and gapped at .020. Make sure your idle speed is set correctly and while you're stopped at lights rev the engine a bit after a minute or so to keep the carbon from building up.
If all else fails, try gapping them at .015 or going down one heat range on the plugs.
Someone here may have a better solution. My experience has been that all you can do is get it as good as you can so they last a bit longer, then live with it.

http://www.pulstar.com/

the new capacitor type-plugs, one of these days, once I figure out if they have a model that will work in a 75 XLH..

.....I'm using Accel Cyclelite Platinum now.....My bike has always liked these...

Can anyone tell me a spark plug that replaces the Harley Davidson #5 plug?

Can anyone tell me a spark plug that replaces the Harley Davidson #5 plug?

I think Autolite 303 and Accel 124
http://www.power-21.com/AutolitePower21i/Competitor.aspx?b=A&pn=hd5&em=True
http://www.power-21.com/AutolitePower21i/PartDetailWindow.aspx?b=A&pn=303

That crosses to an NGK BR6S, Bosch WR8EC, and Champion RJ6C.

I think Autolite 303 and Accel 124
http://www.power-21.com/AutolitePower21i/Competitor.aspx?b=A&pn=hd5&em=True
http://www.power-21.com/AutolitePower21i/PartDetailWindow.aspx?b=A&pn=303

Thanks for the info - FM says 68XLCH magneto ignition use #5 non resistor after engine breakin - I'm not sure what suppressor plug means but I'll try to use the 303 plugs.

Thanks for the info - FM says 68XLCH magneto ignition use #5 non resistor after engine breakin - I'm not sure what suppressor plug means but I'll try to use the 303 plugs.

I didn't see that you were using the plug with a magneto. You want the same heat range as the plugs I listed above but in a non resistor plug.
The part numbers I listed have an R in the number. I can only assume that stands for "resistor"
I'll see if I can find some non resistor numbers.
(btw my 69 FSM shows HD #4 for standard use.)

I did some checking...
I believe that the Champion H8C is the equivelant to the HD5 non resistor.
I use H8Cs or Autolite 4316 in my 69.
Here's a cross-reference chart for that plug in different brands:
http://www.gadgetjq.com/spark_plug_cross_reference_motorcycle.htm

...any suggestions for Magneto-Sportys?
Mine is pretty sensitive for city traffic (plugs become black more and more) and it results to hard starting next cold morning.

Thanx,
Andreas

try a 216 autolite and gap it at 20...4316 is a suppression core plug, not needed on a bike unless you have a radio. 216 is a little hotter than the 4316 as per a CarQuest cross reference chart i checked out.

CHAMPION H10C SPARK PLUG

MEGAFIRE SE-10H
NGK BL6
NIPONDENSO W14L
BOSCH WSAO OR WSA0
AUTOLITE 2677 AND 216

4316 is a suppression core plug

Autolite says it's a non-resistor plug:
http://www.power-21.com/AutolitePower21i/PartDetailWindow.aspx?b=A&pn=4316

I've used a few different plugs in my 69. Those are what works best for me.

*Your milage may vary.

try a 216 autolite 216 is a little hotter than the 4316 as per a CarQuest cross reference chart i checked out.

What's the reasoning behind recommending a hotter plug?

Accel 'U' groove, swapped the bike summer last year and the new owner swapped out the plugs but within a week phoned back to ask what plugs I'd had in there as he couldnt find anything worked as well.

Autolite says it's a non-resistor plug:
http://www.power-21.com/AutolitePower21i/PartDetailWindow.aspx?b=A&pn=4316

I've used a few different plugs in my 69. Those are what works best for me.

*Your milage may vary.



What's the reasoning behind recommending a hotter plug?

My bike will foul out 4316s and BR6s, especially the rear jug. My buddy's 75 will do the same thing to BR6s and BL6s, his is bone stock. I have yet to foul out a 216. And his bike runs better withe the 216s. Another guy we ride with has a 74 and it doesn't like 216s, it actually has burned the ground off before. He exclusively runs the 4316s.