Re: NGK Plugs
 

You can use .030 or .035 both will work fine.

Re: NGK Plugs
 

I gap at .025. Years ago I used a wider gap. Have a crab distributor and would have problems with carbon tracking in the cap. Probably poor cap quality. Tried several different brands, same thing. Dropped to .025 and have never had a problem since.

Re: NGK Plugs
 

So for my stockish 36 flatty 21 stud what p/n ngk's and what gap Gents?

Re: NGK Plugs
 

I use .025" as my experience is the same as flatjack9.

Re: NGK Plugs
 

As the gap is increased the energy that the coil outputs increases. At some point the coil output can exceed the insolating properties of the system. Because the of compression, most flatheads do not require that much spark energy.

Re: NGK Plugs
 

Thanks for all the comments.
When I put the NGk plugs in my 51 EAB stock engine, they ran very well for a few miles. Now I am getting a "fuzzy" carbon build up on the plugs causing power loss.
What gap are you all using? What else would you suggest I check out?
Thanks in advance for the help.

Re: NGK Plugs
 

I have electronic ignition and run .028 with NGK plugs