Single fire
RE: Single fire
ORIGINAL: ragrat64
I put a Daytona Twin-Tec single fire on my 92 Heritage, I think that it starts easier, and runs smoother, In my opinion....
I put a Daytona Twin-Tec single fire on my 92 Heritage, I think that it starts easier, and runs smoother, In my opinion....
Thanks, I know they don't knock out all of the vibs but maybe smooth them out a little. I don't have any trouble starting but once I change it out I could be surprised. I have a 93 Fatboy that I bought used and I am pretty sure that is has never been changed out other spark plug wires that I just put on.
Road Warrior
Joined: Apr 2007
Posts: 1,354
Likes: 1
From: S.W. Florida
RE: Single fire
I just purchased a Dyna single/dual fire module for my FXR. That way I can go either way as my new Screamin Eagle coil and wires are compatible with the Dyna system. I also purchased the Dyna single fire coil that is compatible with the SE wires as well.
My understanding is that with single fire you have more spark energy. In addition you can also retard the rear cylinder slightly in a higher compression engine. I'm thinking about going that route as my engine withe the SE heads installed will be 10.5 to 1.
I also have a NIB Dyna 2000 dual fire module at a great price. It is also compatible with the stock Harley or SE coil and wires. It has a 7 pin connector for an earlier model Evo. If you have a later module with a higher pin count, you'll need to purchase the adaptor cable from Dyna. If decide to go single fire I'll also have an almost new (200) mile SE coil and wire set. The wire set however, will only fit a center mounted coil like an FXR. You can e-mail or PM me if anyone is interested. Trust me, the price will be right!
My understanding is that with single fire you have more spark energy. In addition you can also retard the rear cylinder slightly in a higher compression engine. I'm thinking about going that route as my engine withe the SE heads installed will be 10.5 to 1.
I also have a NIB Dyna 2000 dual fire module at a great price. It is also compatible with the stock Harley or SE coil and wires. It has a 7 pin connector for an earlier model Evo. If you have a later module with a higher pin count, you'll need to purchase the adaptor cable from Dyna. If decide to go single fire I'll also have an almost new (200) mile SE coil and wire set. The wire set however, will only fit a center mounted coil like an FXR. You can e-mail or PM me if anyone is interested. Trust me, the price will be right!
RE: Single fire
Thanks for the offer Buddy but if I decide to go with single fire, I will change everything. My module is a 7 pin and at the moment I am running a SE module on it. Not bad but keep hearing more about the single fire and it would make since.
Advanced
Joined: Dec 2006
Posts: 56
Likes: 0
From:
RE: Single fire
Have a Dyna 2000i in my Ultra. Can't say I felt much difference at low speeds, but at highway crusin yes, a noticable reduction in vibration. I would think there is an improvement in power also, since the pistons are no longer fighting one anotherto a small degree. Installed during other work so I can't give you much more than that.
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Road Master
Joined: Jun 2006
Posts: 894
Likes: 6
RE: Single fire
With the stock set up, dual fire, that just means the plugs fire on the intake and exhaust stroke right?? By changing to single fire (firing on intake compression stroke only) how'sthat going to eliminate any vibration. If anything it may keep the plugs from wearing out sooner. Doesn't sound like it's worth the bother. What I've wanted to know for years is why MOCO used dual fire coils in the first place.
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Road Warrior
Joined: Dec 2007
Posts: 1,854
Likes: 20
From: Eagle River WI
RE: Single fire
I single fire both my strokers with a 96 ss motor I try to eliminate as much vibration as possible I really don't think there is much of a diff between dual fire and single fire It looks cool with 2 coils
Club Member
Joined: Feb 2008
Posts: 18,575
Likes: 4
From: Norfolk, VA
RE: Single fire
Back in the days of points ignition both plugs fired at the same time due to only one set of points for both cylinders. The aftermarket came along with "single-fire" ignition and the factory eventually caught up.......believe it or not, the single fire does smooth the engine out some probably because any unburned fuel doesn't get burned during the exhaust stroke.
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