Coils - Dyna or Suzuki?

[Boondocks]

Here's a quote from Motor Cyclist Magazine, December, 1984 regarding a restoration of a 79 GS1000:

"...If you own a stock GS1000, you own a set of weak ignition coils. Like most other OEM motorcycle coils, Suzuki ignition coils are poor performers. Low spark energy is partially to blame for slow warm-up and overly sensitive carburetor tuning. An engine does not have to miss, backfire or burn holes in pistons to have ignition problems.
Since we chose Dyna for our ignition, it only made sense to use a set of its coils and wires, too. They are easy to install, more than double the energy output from stock and are more reliable. You should also change the plug wires which are molded into the stock coils.
..... if you have to choose between an electronic ignition and a set of coils, leave the points on and take the coils. ....."

Dyna probably wrote the copy for them. I have noticed with few exceptions that the enthusiam and rationale MC mags have for a product are related to revenue from their major advertisers. For instance, the motorcycle mags rationale for "motorcycle oil" came directly from their advertisers that sold oil.

[dietcokeking]

[LEFT]I would like replace the spark plug wires however, because the bike has 30,000 miles on it.

Yeah. Let me tell you how that goes! You go to considerable trouble to access, cut, connect, and seal new wires to 20 year old coils that were working adequately to begin with(?). Two weeks later those old coils will fail. Guaranteed! This is Karma.

[Hoomgar]

Once again Hoomgar comes through with the answer to my question. I want to replace my plug wires before there is a problem, who knows how old the wires on the bike are and I was curious about the glued on wires, I've never seen that before. Anything I should know before I start screwing with it?
Chuck

Sure is Chuck. There is a pin that sticks into the middle of the plug wire inside the socket. You must be careful not to damage it when you remove the old wires and when Dremeling out the holes. I simply grabed the wires and gave them one hell of a pull and twist at the same time and they cam out with a snap! Then I cleaned up the holes with a router bit (in a drill actually because at the time I didn't have a Dremel). If careful, the job is fairly easy and the new wires go right in. Use some good epoxy to glue them back in with. JB weld works well

[Hoomgar]

Yeah. Let me tell you how that goes! You go to considerable trouble to access, cut, connect, and seal new wires to 20 year old coils that were working adequately to begin with(?). Two weeks later those old coils will fail. Guaranteed! This is Karma.

Stop that!

[jeff.saunders]

Are Dyna Coils (or Accel or MSD) better than stock - the answer differs based on the year the original coils were made.

This answer is really a generic answer across the 4 Japanese makes.

To a large part, the coils are only as good as the rest of the ignition system. Putting high output coils on a bike running with points may improve the spark slightly, but they are not a panacea. If you go to the race track, you will not see stock coils on most of the bikes - there is a reason for that - the stock coils just do not cut it - the output voltage is not the same.

In the 1970's the coils fitted to most of the Japanese motorcycles were marginal out of the factory. Most had the molded in plug wires, most generated a very weak spark - many of the magazines lamented about the spark issues with this generation of bikes (although not as bad as Lucas electrics on the British bikes). Roll forward 30 years and most of those coils / wires are very suspect. Many of the spark problems are the wires and plug caps. Yes, you can try and remove the wires from these coils and often successfully replace the wires - sometimes it doesn't work. In removing the wires you can damage the post the wires attach to. In fitting new wires, it does take some work - the wires have to be sealed into the coil otherwise when it rains you'll get a short and lose spark.

Once you start getting into the 1980's, the coils start to improve significantly. Many came out of the factory with removable wires - a big plus.

Often the issue is not whether they are better or worse, but when looking for replacements can you find the resistance you need. Most of the coils fitted to bikes with points are 3.7 ohm to 4.2 ohm. Once electronic ignitions started to surface, you started to see a variety of coil resistances. From 1.5 ohm thru 2.2 ohm to 3 ohm. None of these are suitable on the older points bikes and you have to be careful to match resistance. Some of the newer bikes use some very low resistance coils.

Any coil can fail - they are subjected to tremendous heat by sitting over the engine. They can overheat and fry if you leave the ignition on with the bike not running (ask me how I know this one...). They may fail if you mismatch the coil with the ignition system. Over the years, I have personally replaced many factory coils that quit working effectively. Sometime the first sign was the coil breaking down at higher RPM, sometime they just failed and died.