TOPIC:

wg,

Is this the same coil reg/ac setup for my 78 Z1R. I put a post in about my coil lug getting hot on the wire side. Also, my resistance is 1.5 ohms on the primary for both, secondary is in spec on both.

If your system has a balast resistor, it may have gone bad. This would rase the voltage to the coils and can overheat and destroy them or the CDI box. The after market coils are 3 Ohm and do not require the balast resistor and therefore it should be removed to take advantage of the full energy of the coils. Also if the gap is too large on the plugs, there is too much energy buildup working the same as retarding the ignition this can also overheat the coils. Most likely though, you had corosion in the area of the meltdown which caused a spark to jump in that location and overheated the area. by replaceing with aftermarket coils you cure all the problems with one cure. make sure to put a slightly larger gap in the plugs to take advantage of the higher energy.

Otto Kudrna

otakar,

What should the gap be with new coils? I have a fresh set of B8ES to replace 3 BP7ES and 1 B7ES (no idea why they are different, bought it that way).

Should I bypass the resistor as well on my '78 Z1R?

First of all place the B7 on an outside cylinder. It is a hotter plug and the difference will be noticed less in that position. At the high voltage of an aftermarket coil I have gone as much as .06" (1.5mm) with no problem on a stock motor. If high compression pistons are installed there might be a problem with spark blow-out at higher RPM and the gap can be closed down to .045-.05". You will notice better fuel efficiency with the larger gap because the combustion is much more complete. I run .045" on even stock coils and not the recommended .03" with absolutely no, problem. I have 2 seasons (18,000mi) on this set of plugs on my stock 76,900 and just now I am noticing some misfire, which means it is time to re-gap. On the Z1R you mentioned you have 1.5 Ohm coils. Do NOT Bypass the resistors unless you replace the coils with 3 Ohm coils. A 3 Ohm coil can measure between 2.7 Ohms and 3.1 Ohms. The coils of choice are Andrews, Dyna, Nology, and Martek (if you can find them). Martek has the highest output voltage at 65,000v but the "Blue Goose" coils, as they were known have not been made for quite a few years. They can however be found every once in a while. Nology are the next best choice but are quite expensive. They are the coils of choice for the hyper-built Harley racing motors. I have the Nology Mini coils for my KZ1300(1500) because of their extraordinary compact size. Size is not a problem in your situation and Nology makes a standard size coil for those applications.
Another thing you can do is advance or retard the ignition pick-up coils by a few degrees. Advancing will give you more top end power but less fuel efficiency. Retarding will give you better efficiency but you will loose a bit of power. I would not go more than 4* in either direction.
www.nology.com/info/NolCat09060.pdf

Otto Kudrna

Post edited by: otakar, at: 2007/10/24 08:47

Post edited by: otakar, at: 2007/10/24 09:15

Otto, You wrote, "If your system has a balast resistor, it may have gone bad. This would rase the voltage to the coils and can overheat and destroy them or the CDI box. The after market coils are 3 Ohm and do not require the balast resistor and therefore it should be removed to take advantage of the full energy of the coils."

First, if a ballast resistor "goes bad" its resistance creeps up. When this happens voltage to the coils will decrease I think. The voltage from a ballast resistor doesn't power your IC Igniter (Kaws of this type DO NOT have CDI ignitions but have IC Igniter type). Second, if there is a ballast resistor inline with the power to the coils and 3 Ohm coils are used (such as Dyna), then you are correct that the ballast resistor should be pitched. Last, I think that Nology has a note on their small, 3 Ohm coil saying it should NOT be used on a Kaw of this sort. They call them "Profile Ignition Coils" and the note says, "DO NOT use NOLOGY Coils on point type ignitions on the following motorcycles: Honda VFR, CB, CBX, Kawasaki ZX10, GPz, KZ1000J, Z1, Suzuki GXR-R, (early oil cooled), GS, Yamaha FJ, V-Max." ----Most all of those bikes had either points OR IC Igniter type ignitions and pretty much used 3 Ohm coils OR coils with less resistance and compensating ballast resistors (for a 3 Ohm total resistance at the coils).

I am aware of the note in the Nology Catalog. This is why I called them and discussed that with them at some length, and asked them about the coils being used on my KZ1300. Apperently their coils have been used on KZ1300s for quite a few years with terrific success. The 1300 has the same tipe of ignition as all of the 79 and on Kaws. The balast resistor is between the coil and the ground. V=IxR If your Voltage is constant at 12v and the resistance in the balast goes up the Courant draw goes up with it, because the coil and the resistor is being seen as one load. This is what can fry the power MosFet in the ignition. But since the ignition did not go bad but the coils melted I believe that the coils themselvs were the problem most likely just with a bad connection. Just my oppinion.

Otto

STUPID ME
As resistance goes DOWN Courant goes up. So if you remove the Balast from a stock set of 1.5Ohm coils you blow the ignition. Duh:blush:

Otto

You are using the small Nology coils? Please explain your set up... what type ignition and how do you power them? The folks I buy my carb parts from carry Nology coils and I can get them at a pretty decent price. Why is it they put the note NOT to use them?

otakar,

I was wrong on the resistance. I checked with a digital meter and I'm geeting 4.4 ohms across the primary on each coil. This seems much higher than the range noted in the forum?

confused...