There's the recommended interval in the service manual, but what's the norm for how often we should be changing sparky?

 

Follow what's in the service manual.

 

Anyone recommend a preferred brand?

 

NGK DCPR7E for a stock Evo Sportster.

 

Champion spark plugs are the OE supplier for Harley

 

I use NGK Iridiums. Platinums are good for 100k in cars and trucks, Iridiums longer. As long as my engine purrs , spark plugs are not a priority maintenance item like oil and filters every 5k.

 

Thanks guys. Being up here in NY where it's a bit humid, we have to change spark plug wires and such a bit more frequently than dryer climes. Just looking ahead....

 

Another vote for NKG iridium's. I use then in all my twin cams from the 88 to the 120R. And of course the 883 and 1200's. I won't live long enough for them to ever need changing.

Just be sure to put anti seize on them before installing what ever you select.

 

Have used the stock HD plugs (champions) for years with no issue. I change mine IAW the service manual. Plugs are cheap $$ compared to other HD costs.

 

One day I bought and installed Screamin' Eagle spark plugs, just for the hell of it. I rode about 20 miles and the bike shut down. Would not start. Finally after letting it cool down it fired up but would not rev over 3000 RPM. Limped into my garage and changed plugs back to NGK. Totally cured the problem. Are Screamin' Eagle plugs no good? All I know is they did not work for me nor would I give them a recommendation....