Rebuild: Do i replace my coil etc?

Ok, if i really knew what i wanted/needed it would be. Someone could seriously sell me anything & tell me thats what i needed! :lol:

I'll wait on Loudhvx's suggestions too.

There are several options. In the order I would choose them:

1. Convert to a stock electronic ignition from a 440 or 750 twin. This requires the timing advancer/rotor, the pickup/timing plate, the igniter, and a 2.3 or 2.2 ohm coil. The factory coil for this type is 2.3 ohms. Dyna sells a 2.2 ohm,(gray)coil that matches nicely. You might be able to use a 3-ohm coil with no problem as well. You can get most of the parts on ebay. Last year, someone on the twins forum was a selling a collection of these parts cheap, except for the igniter. But you can easily make the igniter from an HEI ignition module, and it's cheap. home.comcast.net/~loudgpz/GPZweb/Ignition/GPZgmHEImod.html
Advantages: More reliable. No electronic components mounted to engine. No points to adjust. Parts available. Igniter is cheap and abundant. Coil does not use any power when crank is not turning, even if ignition is turned on. Very efficient with power consumption especially at idle, while still giving strong spark.
Disadvantage: Still uses mechanical advancer for timing. If HEI module is to be used, requires sourcing a couple of common electrical parts.


2. Convert a 4-cylinder Dyna S ignition for use on a twin. You should be able to find details for this on the twins website. Basically you take a Dyna S ignition, (I'm not sure if you take one for a 900/1000/1100 or one from a 550/650/750), and use 1/2 of it. I think you have to drill a couple holes to get it to line up. You can buy one that is broken where only one of the pickups works, and you can probably get that dirt cheap if you can find it. You will also need the rotor from the Dyna S. You will need a coil that is 3-ohm or 4 -ohm or 5-ohm.
Advantages: More reliable than points. No points to adjust. Possibly cheaper than using Kaw electronic system. Can use a wider range of coils including stock points coil. Dyna S abundantly available. Longest dwell available at higher RPMs. No external igniter module required. Dyna is a good company to deal with.
Disadvantages: Still uses mechanical advancer. Wastes electrical power, especially at idle because of inefficient dwell structure. Dangerous to coil or igniter if ignition is left on with crank not turning. Uses electronic components mounted to engine, so less robust than Kaw system.


3. Use points to trigger an HEI module. This uses the stock points and coil, but adds an HEI module to create the spark. This allows the points to virtually last forever, and need very little to no adjustment thereafter. It will just need an occasional quick wipe-through with a rag to clean them. This could be done at the same time the advancer gets lubed, maybe once a year. It requires a bit more external electronic components to be soldered together as an adapter, but that is about it. No expensive parts are needed. This is a good project for someone who likes tinkering or playing with electronics. It was a very common project back in the day. I think they were called ignition amplifiers. It can use 2.2-ohm, 2.3-ohm, 3-ohm, 4-ohm, or 5-ohm coils. There are several options available for this project.
home.comcast.net/~loudgpz/GPZweb/Ignitio...heiModForPoints.html
Advantages: No points adjustment needed after initial adjustment. Timing and dwell won't change over time. Cheap. Can use a wider range of coils. Can be made so that there is no coil current when crank is not turning when ignition is on.
Disadvantages: Still uses mechanical advancer. Still requires initial point setup. Requires a little bit of electrical construction.


4. Boyer-Bransden supposedly has an ignition for the 750 twin. I know very little about it. I only worked with one of their ignitions on a BSA. It did work, but seemed very finicky. The construction was unimpressive, and the wires were so thin it seemed if you looked at it too hard they would break. The big advantage here is that it has electronic advance... but I can't say for sure it's the proper advance. It was also pretty pricey, if I recall. I don't know what coils are recommended for it. Someone on the twins forum will probably know about it.
Advantage: Electronic advance.
Disadvantage: Expensive.


5. Then there is the electronic system from the KZtwin forum. I don't really know what to call it since there was no company name, unless I missed it. Maybe the company is called 7thgear, as that's the link on the seller's signature. It seems to be one guy, but I'm confused as to whether he developed it, or he had someone else develop it for him. Early on he says he developed it, but then when questions are asked, he often says he has to refer to the manual, or speak to the developer. Maybe he owns the company, but has an engineer working for him. I'm not sure. But his system seems to be getting good reviews, and, for now, at least, he seems able to respond to questions etc. The main advantage with this one is that it uses electronic advance. The main disadvantage is cost and possibly product support, as the company seems very young. (1 or 2 years?)
www.armbell.com/kz400/viewtopic.php?t=12...tart=60&mforum=kz400


I will have to go back through the thread and check out the links from Motorhead and Mfolks, when I have more time.

Dude you are an absolute master! How the heck do you know so much about this stuff?!

I'll quote & copy your post over to the other thread if thats ok?, you just gave me answers at exactly the right time!