Hello everybody how's everybody doing today, I got a 96 Fatboy I purchased about a month and a half ago seems like I'm having an issue with spark plugs can I get some advice on the best spark plug to use for a '96 Fatboy 51,000 MI running a little bit rich, I do have a 165 main jet to put in the carburetor I'm just wondering what's the best spark plugs to run I hear iridiums from some people to other people say no way help please anything would be of a help to me thank you. Here's a little more information that might help she starts out hold idle but driving down the road and a in town about 31 mph she gets a cough or a and backfires a little more than I think she should the more throttle I give her the smoother she goes, almost like a hiccup at low Cruise speed

 

The Indy shop I use sell NGK spark plugs.

 

Welcome! NGK 7634 BPR5ES-11 or if you want Iridium NGK 2115 BPR5EIX-11.

You'll find a lot of help in the Classic / Evo section since you have a 96 Evo. https://www.hdforums.com/forum/evo-84/

 

Thank you for the help just another question what's your opinion on the iridium plugs like I said I keep getting conflicting information. Are they hard on your motor

 

IMHO....

I will get the exotic, long-life iridium or platinum plugs for my Jeep, because you have to remove the intake manifold to change the plugs...

No need to spend that kind of money on a Harley. The plugs on a Harley are super easy to check, easy to replace, and cheap.... Just get a quality plug in the proper size and heat range.

Champion makes HD plugs and their Copper Plus plugs are virtually the same plug. They are like $5 bucks each.

In my old EVO I used the Champion 12YC5R6A currently about $5 each. (I currently use the Champion RA8HC 6R12 Copper Plus plug in my Twin Cams) I also used Autolite #4265 currently about $4 each. Some use the NGK BPR5ES-11 currently about $6 each.

I see no reason to spend $10+ each for the Platinum or Iridium plugs on a Harley. They give you no performance improvements and their long-life capability is unneeded.

Good luck with your decision...

 

Thank you very much I really appreciate that information you explain things a little bit made a lot of sense

 

You're welcome...

FWIW.... I currently own 4 Twin Cam Harleys. They all get ridden regularly here in SoCal, but because I have 4 of them, none really get "high mileage". Every two years, regardless of mileage, the plugs get checked. If they don't look brand new, they get changed out...

 

I'm also currently running regular plugs in the Evo and Twin Cam. As hattitude said, they're easy enough to check and change if needed.

 

@hattitude knows his ****, I ran the Screamin Eagles in my TC88, after a brief conversation with Hat, I went with the Champion RA8HC 6R12 Copper Plus and I could tellabsolutely no difference. Not to mention I throw in a new set every year.

 

use whatever the owners book says. very simple