Spark Plug Suggestion for those using CB 044 heads

Does your CB heads take 14mm plugs?

Whats the heat range on the harley plugs?

Part# please.  I roll with the 44s.  

Hi guys; don't quote me on this but I believe the plugs on the 044's are 12 mm?  Spark plug no. is 6R12. Not sure if the number will give you the heat range? Hope this helps.

I have these heads.  Plug supplied by maker - NGK 7512 - D6EA

Those didn't work for me; that's what the post is about. The Harley Davidsons are US made and more expensive but better. Looks like it's the same heat range; 6?

Maybe you are being oversold on the Harley Davidson "mystique".  I picked this up on the HD Forums board from a discussion on the 6R12:

So you should/could run the Champion RA8HC to save even more money, as that's what HD uses. Champion just rebadges them with the HD logo.

I use NGK DR6EA in my ported mini wedges without any issues.  The only reason I don't have D6EA is the local Auto Zone did not have them in stock at the time I was there to buy plugs, and the "resister" version of the plug is a non-issue for me.

Are you sure you don't have other issues that are making you run ultra rich and fouling your plugs?  (Perhaps the black smoke and hissing sounds might be a clue?)

Also, just how "big" are your big valves and how "ported" is your porting job?  You only have a 1915, you can easily go off the wrong end of bigger-is-not-better.

Good info; had I known that I would've gone with the Champions. My heads are just the basic 40 by 35's; don't have details on the port job as I didn't do it. Now that you mention it we also leaned out the mixture too. Now the car is working flawlessly. I guess I'll go with the Champions next time.

As long as your runninga high grade fuel ^ is fine but if your trying to run  a regular blend  id go 7 or even 8

Spark plug heat ranges are not interchangeable. Some makers get hotter the higher they go numerically, and some the opposite.

 

A NGK D6EA is a pretty hot plug, which is fine if you are running lower compression and a richer mixture. This is the normal state of tune for most ACVW Type 1s. A "hotter" plug keeps the electrode hot for longer after the spark event, which has the net effect of keeping the plugs from fouling.

 

Higher compression engines with mixtures closer to stoich (14.7:1, A:F) need colder plugs to keep the electrode from becoming the glow-plug, and turning the engine into a diesel. NGK plugs get colder the larger the numbers. The coldest plug you can readily find without spending $20/ea is about a 9-series heat range.

 

Generally speaking, you want a plug that is hot enough that it never fouls, and cold enough that it never starts pre-ignition. This is going to vary widely with carburetor mixture, total timing, dynamic compression, and general state of tune. There is no "one-size-fits-all" plug for an 044 head.