Hey Guys I just bought my first HD, it an 1982 FXS lowrider, I have no ehistory on the bike. My question is are the duel plug heads stock or after market?. I'm sure I'll have many other questions as time passes and I clean it up over our long Canadian winter. Thanks in advance for you r feedback

Hufee

 

Duel plug not stock I did a 93CI shovel with duel plug heads and single fire Don't know if the 2 plugs per cylinder helped but the bike was impressive It looks good with all the plug wires running around You can also run compression release plugs off the unused plug holes if you ever want a high comp stroker motor

 

Not stock but a very nice addition for a shovelhead , solves a few chronic problems like fussy starting and dirty spark plugs . You can run the cheap pump gas without knocking and pinging . I've dual plugged every shovel I've ever owned and about 70% of the rebuilds I do for people . When doing a tune up you may find the bike will run better with the timing backed off a few degrees . Looking in the timing hole you see the mark on the flywheel centered is 35 deg. , move the mark to the rear of the hole so you just see it that,s 2 1/2 deg retarded . I've found that or a hair more is the sweet spot for shovels & dual plugs .

 

Great if it's kick only.

 

Shovelhead combustion chambers were very inefficient. I've had 2 that were dual-plugged.
It will help burn off more of the air/fuel mixture.

 

Yah definately not stock my dad runs dual plugs on his 74 Kick only with some other mods to the motor he had it blue printed at Lake shore H-D in like 1980 and its one of the best sounding bike Harely ever built. By the way his 74 is for sale if anybody is looking.

 

I have to ask Twizted Biker, Did you intend to explain timing the ignition this way ? I have not posted before on this forum and would have preferred to do it in private, but that is backwards, I hate to say, leaving the front of the hole is retarded as the piston would be closer to TDC in which the firing would be later (retarded). Timing the ignition at the rear of the hole would fire sooner (advanced) Hate to see folks doing their timing incorrectly as that is one of the main benefits of dual plugged heads when used on a Hemi Head design

 

I go along with Twizted here the line on the wheels should be centered at the normal advance mark (front cylinder ) for timing By bringing this line to the rear slightly The bikes seem to run better Maybe because I run the 52 with the line at the rear of the timing hole (circuit breaker ) or maybe we're both retarded

 

Ran a custom built 96" kick only pan as described by Twizted and it ran like a raped ape.

 

This may come as a complete shock to many folks but dual plugs ain't what most think. We have dual-plugged Pans, Iron & Evo XL's, Shovels, Evo's and Twin Cams, over the almost 3 decades we have been in business.
Small engines, as well as large powerplants.
NEVER had we EVER experienced anything earth-shattering, in regards to doing so, while dyno testing/tuning later, and trust me, we shook the trees.
Machine heads, 4 plugs, 2 sets of wires, multiple coils, specialty coil mounts, usually along with a single fire ignition.
Let's see...........650.00 plus dollars for no more torque, or hp, in a street driven bike.
Think I'd rather have a bar of soap.
Scott