Topic: goldwing coils

[rstarcher]

Years ago i read that using coils off an early Goldwing was a common upgrade to the ignition system for the CB750.  I bought a set off ebay but they've been sitting in the box ever since.  I've been working on the bike a lot this year (mainly due to the info I've found here) so I'm thinking this is the year to actually install the coils and see if there's an improvement.

So out comes the box and I test the coils.  One measures 2.8 ohms and the other is 2.2 on the primary; both are around 16k on the secondary.  So now I'm wondering if the 2.2 ohm is safe to use or will it hurt the Dyna S ignition.

Bike is a CB750K1 with Dyna S (and currently stock coils).  I know the Dyna is good with 3 ohm coils...

Any comments on whether it's okay?

thanks
Randy

[TwoTired]

The definitive answer is "maybe".


I think Dyna specifies 3 ohm as the minimum for use with their S unit.  Lower ohms will draw more current and tax the driver in the dyna.  It will run hotter and closer to its limit of operation.  The parts have a maximum specification which they must meet.  They often exceed their specs but no manufacturer will garantee beyond their specification.  Most derate the application to ensure longevity.

You may try it and find it works fine.  Then again it may cook off and fail at some future date.  Certainly running at a higher temperature will shorten it's life, but knowing if that is 5 minutes or 5 years is guesswork unless you have access to the internal parts specifications.

It also helps to know if you will ever run the engine at high temps and in the mid day desert sun.

Cheers,

[rstarcher]

My riding tends to be daily commute and some cruising trips...20 to 60 minutes at 40 to 60 mph mostly, generally keeping the bike between 3000 and 5000 rpm.   Afterwards there is at least a few hours to cool down before restarting.

I live in Ohio and ride from April/May until September/October.  So hottest is around 95F and coldest around 55F.

Randy

[eldar]

I dont remember gw coils being that low on the ohm rating but then I cant remember exactly when the gw came out. I know the 79 750 had lower ohm coils.

If you are going to try it, make sure all your connections are perfect to minimize the resistance which can lead to more heat but also make sure the pickups are clean and secured onto the plate.

[bryanj]

Goldwing coils aint 12volt as they run with a ballast resistor!!

[Ibsen]

The GL coils are 2.0 ohm coils:

http://www.randakks.com/TechTips.htm#38

[rstarcher]

Glad I asked, guess I won't be using them.

Randy

[eldar]

They are 6V coils but you can chuck the ballast resistor and still use them on a 12v system but the ohms will drop even lower.