Dual Plugged Heads – What Plugs?

[herman1253]

Last summer I finally got a Shovel, it’s a 78 FLH and I love it!! What plugs are you guys running? It’s been duel plugged â€" one long threaded and one short threaded plug in each head. The motor is 74inch, Crain Hi-4 ignition, CV Carb and true duel exhausts.

[76shuvlinoff]

 I run dual plugs but both are long reach, Autolite 4265s for me

[CraigArizona85248]

My panhead is like your shovel... short-reach plug on the left side, long-reach plug on the right side.  For the short reach I use Autolite 4275, for the long-reach I use Autolite 4265.

-Craig

[hkd76]

I've been running RN12YC on the left side and RJ12YC on the right and have been happy with them.

[Pilgrim]

Herman, do you know that when you get to messing around with that thing, you set the timing different than you do with a single plug?  It takes a couple degrees less advance.

Pilgrim

[herman1253]

Thank Guys,

Yes Pilgrim i know about the timing, my bike was fitted with four long reach plugs buy the last owner, two of them with spacers to make them into short reach plugs, I'm rebuilding her and want to fit the proper plugs.

Pete.

[randallwhitman]

If they're stock heads that have been altered for the dual plugs, you'd better measure those spacers carefully so you don't have a piston/sparkplug collision.   

[dave_9113]

I really like Bosch platinum.  Bike is kick only. Very hard to foul.  Run them in my Evo too.   

dave

[arkbubba2]

I have a set of HD crown heads that have been duel plugged and both sides have RN12YC plugs. Am I missing something here?

Thanks,
Lyn