Misc: Ignition Twin Points Ignition

[Monkeypants]

Yes it is.
With the close gap, both sets of points are closed longer and there is a voltage drop. In that state, the coils do not charge properly.
The spark to the rear cylinder is lost. Open the gap a bit and away you go.
I discovered this at about 400 miles from home. At the same time I learned about the Daichi "upgrade".
After that I cornered the world market on NOS Lucas points, no more problems.
That was at least 40,000 miles ago and the same Lucas points are still in place.

Glen

 

[oexing]

Dwell angle on a twin should not be an argument at all. Remember that even V 8s had a simple distributor and one contact breaker for many decades. Yes, in these engines dwell angle is critical definitely but not with twins or fours.
Not my project but I´d go for a Saab distributor and dual coil ignition with one contact breaker once you got a decent generator on the bike. With the correct Saab type - watch rotation sense because of advance device in it - you then get a fat spark from battery coil ignition, no weak sparks from poor mags, be it electronic or traditional . In case you were not happy about the contact breaker (weak argument) you could have a Lucas Lumenition to replace the breaker. There are a few electronic ignitions for classic distributors for that mod but basically a contact breaker is quite allright, for 100 years in all cars and bikes they were good enough and had no complicated failures to worry about. With the Saab type you have to grind one breaker lobe for the 50 degree Vincent engine, I´d prefer this over having two breakers and one lobe . And certainly you need an adapter with a ball bearing to clamp the distributor to the engine, no big deal on the lathe. As the saying goes: Keep it simple, stupid . . .

Vic

 

[Monkeypants]

Two sets of points allows easy individual timing between cylinders. I played with that ages ago and got some extra hill power from it.
All I can say is that it's been a very easy to live with system and I've covered a lot of miles with it.
The prior owner told me " you are going to love the easy starting electronic ignition on this bike"
He rode the bike for 12 years in OZ without ever looking under the points cover.
He assumed it had electronic ignition because it started much easier than his three other Vincents. He mostly rode this one as it was the easy starter.
Glen

 

[Chris Launders]

I have a twin points system on my Norvin, it uses the standard ATD and twin sets of "Rev-Tech" aftermarket points for Harleys (the ones where they have a set of points for each cylinder), they are no longer made I think but I have several sets as a custom shop on Lincoln was having a clear out and had them at £7.50 for the two WITH condensers. they are really well made and have been utterly reliable, I'm sure some other aftermarket company will have quality points similar as a lot of Harleys still use points. For coils I have two 5 ohm Dyna ones, again never had a problem.

 

[Pushrod Twin]

Yes it is.
With the close gap, both sets of points are closed longer and there is a voltage drop. In that state, the coils do not charge properly.
The spark to the rear cylinder is lost. Open the gap a bit and away you go.
I discovered this at about 400 miles from home. At the same time I learned about the Daichi "upgrade".
After that I cornered the world market on NOS Lucas points, no more problems.
That was at least 40,000 miles ago and the same Lucas points are still in place.

Glen

I take it from that it is the synthetic, nylon? rubbing pad which fails on the Daichi points, causing the gap to close?

 

[Pushrod Twin]

. For coils I have two 5 ohm Dyna ones, again never had a problem.

Thanks. Interesting selection for coils. I have just had 3 ohm coils recommended by a knowledgeable Brit Bike parts vendor. He suggested to avoid 5 ohm coils, they are for electronic ignitions. He offered me condensers, but didnt mention their capacitance rating.
Do your condensers have a capacitance rating written on them, ??? micro-farads?

 

[Chris Launders]

Whoever recommended the 3 ohm coils has it the wrong way round, they are for electronic ignition, 5 ohm for points. I will have a look at the condensers later but would be surprised if they do give the rating.

 

[bmetcalf]

This from Mistral on the electronic RITA muddies the water:

 

[Michael Vane-Hunt]

I run a McDougal/Harley electronic ignition and definitely use a 3 ohm coil.

 

[Bill Thomas]

Strange world !.
Feked.com says 4.5 for points, Can also be used for electronic ignition !!.

I see Bruce is talking about a single cylinder, Maybe different ?.