TOPIC:

I have found the Dynatek DS2-2 ignition listed for  the 1980 kz750G twin . I assume that this kit requires modification for use on the twin cylinder bike,
since it is also listed for a variety of 4 cylinder Kawis.
Do the changes to the charging system etc.on the later twins prevent this kit from being used on the early twins? (Mine is a '76 750B1 in stock condition)
Any feedback on this is appreciated.

Thanks

The four cylinder bikes use a "wasted spark" ignition system, since they fire the plugs using two coils, not four.  Twin cylinder bikes are different, and don't waste spark in the same way.

A bikes charging system is unrelated to the ignition system.  

This topic has been discussed many times over the years on this site.  Many of the folks who provided excellent responses in the past are no longer around.  You can search the site using google.  Try this.

site:kzrider.com 750 twin ignition

thanks- I didn't think the charging system was related- just wanted to be sure.

People have used the dyna ignition on these bikes successfully before. Basically you just connect half the ignition from a 4cyl bike and it will work with one coil.

These twins have a relatively poor combustion chamber design and low compression. That’s why a good ignition and advanced timing really wakes them up. I don’t know what the ignition curves look like from DynaTek - I haven’t seen them published anywhere but I would guess they are not optimized for the twins.

If you were already planning on buying a coil and plug wires, for not much more money you can get an optical ignition from PowerArc. This has an ignition curve specifically for the 750twin with triple spark. I have used them on two bikes and they are worth it. It also helps to use a spark plug with a protruding electrode to get it further into the combustion chamber. 

Thanks for that info. I've also heard good things about an optical ignition kit from Newtronic. 
Do you have any personal experience with that product? That kit costs less- no doubt because it does not include the coil and plug wires.
The PowerArc kit does include those items, correct? also- can you recommend a certain spark plug? My riding style is purely recreational, 
Bike is stock except for the Alphabet header and rejetting for the exhaust.

Thanks for your help,

Russ

I don't have any experience with Newtronic so I can't comment.

PowerArc comes with coil and plugs - you must run a resistor plug with their setup. On my last bike I was running a BR6ES with the Powerarc setup and was happy with that. On my new twin that has 86mm bore and higher compression I will try the BPR7ES or potentially a BPR8ES. the additional "P" is for protruding electrode i'm worried it might get too hot but testing will tell.

FYI - one downside of the Powerarc setup it you loose the ability to turn the engine over with the crank on the ignition side. Its not that big of a deal to advance the engine with the kick-starter though for doing valve adjustments etc... it never bothered me except when i was degreeing cams and then I had the stator cover off and could turn the engine over that way.

I'm using BR6ES plugs now with the stock ignition. If I go to the Powerarc kit and a "P" spark plug do I want to switch to a cooler plug?

I’ve only used the BPR6ES on the stock points ignitions when I was having trouble with it breaking up at higher RPM. It helped but didn’t solve my problem. Then I switched to Powerarc (sold through C5 ignitions-now defunct) and BR6ES.  That combo worked great and was easy to start and was good for normal street riding and that seemed to work fine. Zero complaints. It’s been going strong for 7 years and my friend owns and rides that bike today.

The main reason I’m going to use the BPR7ES plugs in the future is I have gone from 749cc to 906cc on my latest project. I want the spark further in the combustion chamber since the bore has gotten so much bigger. I’m going with a cooler plug because the protruding electrode should run hotter in theory and because I have increased compression as well. I also will be taking this bike to the track so it will be running hotter there too. I won’t know for certain until I can test it. I am contemplating a dual plug head if I have issues with combustion, testing will tell.