Twin plug setup

[Gus58]

Got the shovel twin plugged and need to know a couple of things if you please.... What plugs should I use? Would I need to retard the timing a bit to compensate for a quicker burn? Can anyone recommend a good set of coils to run with this setup, its a street bike so they don't have to be the latest and greatest with a huge pricetag to match. I'm running points..... lastly, is there anything else that needs doing before I fire her up??? Cheers Gus

[jamba]

My brother has twin plugs in his shovel. Original sparkplugs will work fine. Also he's got old Accel coils and points, and timing is normal. If you have a near stock cam, you don't need to retard timing.

[Gus58]

running a b grind with mild port job and a 48mm s&s carb.

[jamba]

Originally Posted by Gus58

running a b grind with mild port job and a 48mm s&s carb.

My bro has S&S super E. I'd still start stock timing.

[76FLH]

Well I'm not 100% sure about this, but I think you need to run two 6 volt
3 ohm coils in series because points like 5 ohm coils. Two 6 volt coils in series would be like a 12 voilt coil, Two 3 ohm coils in series would be 6 ohms. Does this sound right to you all? Lower than 5 ohms burns up the pionts.

I am sure about this, you want to run the timing at about 5 to 7 degrees less total advance. Two plugs give a faster better burn. Put the timing mark to the very front of the timing plug hole.

Plugs, you did not say if you have short or long reach plugs. I run Autolite 4265's on the long side (left) and 4275's on the short side (right).

Bill

[ToddM]

Originally Posted by 76FLH

Well I'm not 100% sure about this, but I think you need to run two 6 volt
3 ohm coils in series because points like 5 ohm coils. Two 6 volt coils in series would be like a 12 voilt coil, Two 3 ohm coils in series would be 6 ohms. Does this sound right to you all? Lower than 5 ohms burns up the pionts.

I am sure about this, you want to run the timing at about 5 to 7 degrees less total advance. Two plugs give a faster better burn. Put the timing mark to the very front of the timing plug hole.

Plugs, you did not say if you have short or long reach plugs. I run Autolite 4265's on the long side (left) and 4275's on the short side (right).

Bill

When I dual-plugged my Sportster, I had to run a longer reach plug on the right side do to the thicker boss. I can't remember what coils I used, but I think I bought a kit from J&P Cycle. The price was right and it saved me a lot of time setting it up. The timing should be left alone. More efficient burning doesn't make a difference in when the spark plugs should fire.

[Gus58]

Thanks for the info fella's, the 2 six volt coil setup sounds like it'd work, some confirmation would be handy. I've been told to run low ohm coils, but all the twin fire and single fire stuff has me a bit bamboozled. I've got a "your shopping cart" page open loaded with goodies at J&P but really want to know which coils to get before hitting the "checkout" button. Saves heaps on postage to Australia if I can bundle it all.

[bigal51]

I ran a dyna single fire ign on my shovel when I had the duel plugs installed-I did retard the timing a couple of degrees. S&S 93 inch,ported heads and a cam that was similer to the b-grind-in the 5 years I ran that set-up I had no problems with the ignition except 1 burned out coil-Al

[HDWRENCH]

For the twin plug you will find most times that you will have to retard the timing over a single plug set up by 3-4 * to prevent ping. As for coils make sure you ohm the new one's as coils can be out of spec and cause you issue's down the road ( or maybe on the side)

[Tony S]

Originally Posted by 76FLH

Well I'm not 100% sure about this, but I think you need to run two 6 volt
3 ohm coils in series because points like 5 ohm coils. Two 6 volt coils in series would be like a 12 voilt coil, Two 3 ohm coils in series would be 6 ohms. Does this sound right to you all? Lower than 5 ohms burns up the pionts.

I am sure about this, you want to run the timing at about 5 to 7 degrees less total advance. Two plugs give a faster better burn. Put the timing mark to the very front of the timing plug hole.

Plugs, you did not say if you have short or long reach plugs. I run Autolite 4265's on the long side (left) and 4275's on the short side (right).

Bill

Can I run Autolite 4265 Spark Plugs on a bone-stock '82 Shovel? Are they too hot? Too cold?