Topic: Oh m'god! I bought a DynaS ignition and I didn't know!

[mennedy]

I am swapping a 74 550 engine into my 78K and discovered that for very little more than the standard points/condensers, I could step up to the DynaS. Gotta discount so I ordered. They didn't have the Iridium plugs but I can get them elsewhere.

I checked FAQ's for Iridium plugs and then searched them in Tech Forum. I unearthed some threads that were pretty heated and technical and probably best left to lie. I do have two questions arising from my "wide eyed trip through the threads". One, do I need to step up to Dyna coils too or are the 78's okay? Secondly, do I need to change my spark plug wires to resistor/non-resistor wires. I don't know what is on there now and since it is not running I can't do the AM radio test.

I don't want to fry the new ignition or something else it will take forever and $1,000 to fix so your advise is very much appreciated.

   Marty

[Bodi]

The stock (5 ohm) coils are fine, you'll get the benefit of trouble free "set and forget" ignition timing. If you get 3 ohm Dyna coils you get a considerably stronger spark and use a fair bit more electrical power but Dyna suggests them (they say to use 5 ohm on the 400F - its alternator is known to be just adequate for the stock load).
Dyna coils don't exactly bolt right on, you have to file down the Honda mounting brackets a bit. Buy the Dyna wires for their coils as you get everything you need and, otherwise, finding the wire and terminals is troublesome. The plug wire routing is a bit different from stock but it isn't too hard to figure out.
You should use non-resistor wire as on the original coils. Use non-resistor caps unless you have non-resistor plugs, I don't think Iridium plugs are available without resistors. You can re-use the stock plug caps or just get get new NGK ones, if you have to get resistor ones go with 5K and if you really want you can unscrew the plug contact, remove the resistor and replace it with a metal slug.