Topic: Plug gap for Dyna ignition

[fdbrat]

1975 cb750f1 with the Dyana ignition and the extras little dyna s box.

I'm running resistor caps at 5k ohms. 8hs plugs I believe...

What is this extra box for by the way?

Ok main question. With this setup what should I gap my plugs to?


Thanx fellas.

[Jerry Rxman Griffin aka MuthaF'er]

That's the earlier Dyna III system. I have one. Works great. Throws a mean spark along with my Dyna 3ohm green coils WITHOUT resistor caps. Sucks lots of juice from the electrical system set up that way but I can live with sometime undervoltage. Can't say for sure but I'm thinking it acts like a condensor perhaps to hold charge then throw a hotter spark? Anyone with a real answer?

Gap them factory.

That box is no longer available. If it cooks on you Dyna told me they will rebuild them for us.   

ps F1 is the 1976 model. most of which were built from 4/75 on. 1975 is called either a K0 Super Sport, F or F0 built from 1/75 through first week of 4/75.

[TwoTired]

The dyna-s is just a coil trigger.   Dunno if the Dyna II sends more voltage to the coil.  But it seems unlikely.   With stock coils, you keep the stock gap.  You could open the gap to about .035" if the coils are 3 ohm.

[HondaMan]

That's the earlier Dyna III system. I have one. Works great. Throws a mean spark along with my Dyna 3ohm green coils WITHOUT resistor caps. Sucks lots of juice from the electrical system set up that way but I can live with sometime undervoltage. Can't say for sure but I'm thinking it acts like a condensor perhaps to hold charge then throw a hotter spark? Anyone with a real answer?

Gap them factory.

That box is no longer available. If it cooks on you Dyna told me they will rebuild them for us.   

ps F1 is the 1976 model. most of which were built from 4/75 on. 1975 is called either a K0 Super Sport, F or F0 built from 1/75 through first week of 4/75.

The Dyna III was the "fix" for the too-short-dwell problem of the Dyna S units. They artificially make the OFF time to the coils longer (about 5mS) so they can fully discharge, which is the main weakness of the Dyna S (it won't let the coils discharge fully above 5800 RPM). I had a Dyna III until it went belly-up, worked good before that, all the way to 10k RPM. The Dyna S that replaced it caused weak spark (and died 18 months later). It wasn't until I developed the Transistor Ignition that I ever delved into the "S" to find out why, and then it became painfully obvious!