new dyna coils cracked

I understand your frustration totally,, but you should have gone back to the dealer again and let him know what Dyna told you, if you hadn't already. Whether he is a member here or not makes no difference, a public forum like this isn't the place to air out the problem. It's with him, he isn't going to screw you over.
I personally have no idea why the coils would do that even if they have the wrong resistance.
I had to modify my mounts some to get the dynas to fit my 650. When I first mounted them, they were pretty tight on the frame and was putting stress on the coils. And had to install nylon spacers on the primary end to keep the screws that hold the wires on from grounding out. I used longer nylon spacers on both ends to drop the coils a bit. Other guys have just used tape on the original metal mounting spacers. Hopefully, this wasn't your problem.
Ride safe.

Before selecting a coil, check the coil primary resistance requirements as specified by the manufacturer of the ignition being used.

from www.dynaonline.com/english/dyna_coils.htm

So, what does the Factory Service Manual say the primary resistance should be?

I don't have a manual for the 900/1015 motors or I'd look it up.

You are complaining about the lack of support from us, yet you have not even picked the phone up and called us - or attempted to email us since you received the coils back from Dyna...

The coils splitting is not likely to have been caused by the resistance. As others have stated, many, many other bikes have green coils with points. The negative of 3 ohm coils with points - it tends to cause the points to pit a little quicker than with stock coils - but you're looking at 2-3,000 miles of life versus 3-4,000 points life... the positive of the green coils is they generate a better spark - something most owners benefit from - especally with cold blooded, hard starting bikes. The 3 ohm coils are also a better match with the Dyna-S ignitions - something the majority of owners also switch to at some point.

Dyna 3 ohm coils are a nominal 3 ohms - when you measure them you get 3.3-3.4 ohm readings. The factory Kawasaki coils will read from 3.4 - 3.8 ohm when new.

As stated previously, and others have stated, you likely have other issues causing this problem.

How old are your points / condensors? If the points are pitted, it's time to replace both the points and condensors.

I suspect your regulator has failed and your bike is over charging badly. Check your battery fluid level and see if any of the cells are down on liquid - if so, a sure sign the bike is over charging and your regulator is bad.

If the bike is currently back firing through the carbs, you may have mis-wired the coils and have 1/4 and 2/3 feeds reversed, or have the plug wires running to the wrong cylinders. One simple way of checking is to remove the plugs from the head, put them in the plug cams and ground them on the cylinder head. With the ignition on, turn the engine over slowly with a wrench on the end of the crank, when you see a spark on a plug check that cylinder is at top dead center. You can also look at the ignition advancer and see if it matches the markings on the advancer.

Once you get the bike running, you need to check the voltage at the battery - at idle you should see 12.5-13 volts. as you bring the rpm up, the voltage reading will rise until it caps around 14 volts. If the readings continue to climb past 15 volts your regulator is bad for sure. In some bikes you will see readings as high as 18 or more volts - enough voltage to cause major issues.

Often you would notice lights getting brighter and brighter as the voltage climbs.

Post edited by: Jeff.Saunders, at: 2007/08/30 08:46

Thanks Jeff for that post. That helped me out big time.

I don't know why the coils cracked around their middle. Never have seen that happen. Have been at motorcycle mechanic stuff for almost 40 years. The Dyna coils tend to crack around the metal arms that are used for mounting. This cracking is normally associated with age and heat.

As far as using the green coils with points, there is absolutely no reason not to other than the a set of points will not last quite as long... certainly won't cause the coils to crack. The 5 Ohm coils that Dyna suggests just extend the life of a set of points a bit but either the green or black coils work fine. I would ALWAYS recommend the green coils because when the owner upgrades to an electronic ignition, my opinion is that the black coils don't produce as hot a spark as the green with the electronic ignition and actually perform no bettter than the OEM coils did.

I think for a new coil to crack down the middle, it would have had to been mounted grossly wrong (doesn't sound like it in this case) or the coil had to be grossly overheated. I have left a key on overnight with green Dyna coils (don't tell anyone I made a mistake hehe)... and it didn't crack the coils. I would use a multimeter and check the resistance of both the primary and secondary windings for a short... the short will generally be caused by MAJOR overheating and this could only be caused by the voltage regulator being dead... in other words very high voltage feeding the coils.

As has been noted, when the bike only backfires when coils have been installed, it is likely the black and green wires from the points have been installed on the wrong coils... black to 1 and 4 and green to 2 and 3 coil. Trace the wires up to the coils and see what plugs the plug wires go to. Normally, the 1/4 coil is on the right as you sit on the bike.

As far as how this issue has been handled, I personally would have been embarrassed to have a customer complaining and making demands in this forum without having actually contacted me. Have to take my hat off to Jeff Saunders for not ignoring this guy or telling him to pound sand after his temper tantrum. That stoic Brit demeanor serves you well!

For Sandy/Patman: hehehe Bud!

Stoic Brit.......I like that !:laugh: :laugh:

BTW Jeff.......since your an old red coat....:laugh: do you have a good recipe for tartar sauce ? Or is malt vinegar still the rule for fish and chips ?:woohoo:

Post edited by: arai60, at: 2007/08/30 21:50

Wow, I am amazed over the patience, restraint, and quality of the folks on this forum! And especially Jeff Saunders: Sir, you are a gentleman and a class act! After all that, you persist in trying to help this guy, and merely chasten him a wee bit for not contacting you or Rob. We should all take it as a life lesson.

13thLevel, victims will never be victors. You're upset,but everyone that has posted has both expressed empathy and tried to help with very little info on the issue. You really need to listen to them and take their advice and instruction. You will fix the problem, learn, have a great bike, and feel accomplished that you have done so. Give them a chance to help you.

And give Jeff a call at Z1, you know what to say...

Well I guess I burned alot of bridges here. I feel like an ass. Sorry for being such an ass.
My bike obviously does have other issues. One of the new coils (black) failed on me today. And my headlight burned out within seconds of starting the engine (I assume this means the regulator is faulty). Karma sucks.
Oh and the backfiring was indeed crossed wires. I had connected the green to green and black to black, for some reason mine are backwards and I had to connect green to black and black to green....?
So in the end, I'm the moron. Oh well I'll live and you all will get over it....:dry:
Hey does anyone know if I can purchase a single black coil and a voltage regulator from z1.....I'm to embarrassed to call and ask.

I'm impressed that you came back on and admitted you were wrong and apologized, Good man.
First things first, now that you know you have a problem, do you have a manual so you can go through the charging system tests correctly before you buy a new regulator? As noted earlier it may just be faulty wiring. It sounds like you have lost the ground connection on the regulator, but without testing it you don't know for sure.
Check the battery level and get it full of distilled water. I would put on the one good orignal coil, and do the tests using that one, then when you find the actual problem and get if fixed, repace the coils if need be.
As I said earlier,, I'm impressed.
Ride safe

13thlevel wrote:

...Sorry for being such an ass...Oh well I'll live and you all will get over it

Of course that's true, but now I (and probably others) think you're a pretty good guy for coming back this way, instead of disappearing into angry oblivion...

13thlevel wrote:

....Hey does anyone know if I can purchase a single black coil and a voltage regulator from z1...

There's a couple different regulators listen on the page not sure which one you need. There's THIS ONE , or THIS ONE which mentions your '76 900 in its listing...

Is THIS (Dyna Dual Output 5.0 Ohm Coils (single) DC8-1) the coil you mean?

Wow 13thlevel... It took some sand to admit you were out of line. If you use the experience as a character building step, it was of use. If you keep doing it... well, you can guess what I don't need to say. Call Jeff. Tell him what you need. Buy a combo reg/rec and ask for help installing. Your rectifier is an old piece of junk too... the thing is over on the left side of the battery box. The little black square thing with wires crossing back and forth. Get rid of it when you get rid of the regulator by going combo. Anyway, good luck with the bike! I have two 76 KZ900s...

wiredgeorge wrote:

Wow 13thlevel... It took some sand to admit you were out of line.

Too true Joe...good on Ya,Bud.

Call Jeff and get it all sorted out,and then YES...get the upgraded rec/reg combo like George said...SO worth it!
Eliminate the old-school garbage,because it IS...garbage...old and worn,and too unpredictable,just ask Me.We got stranded out of town a few years ago because of MY regulator.(long story with a happy ending)

Start at the beginning...start fresh and go through it all.Eliminate the headaches and the doubts.

Jeff is a great guy.I've been dealing with Him for a few years now,and I have had absolutely NO complaints.His service is outstanding and He's more than willing to discuss any issues You have with Your bike.If He has the time to spend on the phone,take advantage of His knowledge,and learn from Him.
And it's not just ME,that He takes time out for...He has helped a LOT of Members here.So You have to appreciate the replies in this thread,in regards to Jeff and how repsected He is here on KZrider.He's an asset.
I could go on and on,but I think You get the idea...

Again Joe...good on Ya,BudB)

Good luck with it all,and post back on it.