Won't start after rebuild

What is ohm reading between plug caps (secondary winding) on the '82 coils. How do these readings compare with those from the '85 (between plug caps)?


New solid core plug wires themselves should have no resistance. The resistance between plug caps results mostly from the secondary wiring inside the coil, plus whatever resistance is built into the caps. At least that's my understanding.


If not already done, would assure good tight connections between plug wires and coils (and proper fitment to coil).


Given perfect coils, perfect wiring connections, perfect wiring to coils, ample voltage to coils, and perfect wiring from Igniter -- this leaves very little to explain the weak orange spark, except for the coil output reaching the business ends of the plugs.

kawsakiman wrote:

i'm thinking his cam timing is off.

.......Have you verified that the cam timing is correct yet ?? Could also cause the somewhat low compression . In your orig post you didn't mention swapping electrics during the rebuild . It ran before the rebuild ? That would lead me to first check factors affected by the rebuilding process . Cam timing , valve lash , IN and EX cams swapped (if possible in 750)and proper wiring reconnection (this one you seem to have completely investigated). Any of these things could cause symptoms that you are experiencing , except possibly the orange spark . Good luck to you .I know how you feel , I have a very nice '82 GPZ750 that I haven't been able to get running properly . Post edited by: hannah1, at: 2007/12/24 13:10

Post edited by: hannah1, at: 2007/12/24 13:20

The flying cam/mechanical advance isn't on backwards or reversed - it only goes on one way.

Are you real sure about that?

I am reasonably certain (because I have done it) that the rotor will go on the shaft 180 degrees out. And the bike wouldn't start

So, if you have dismantled the timing advancer to clean and/or lube it, it is entirely possible that the rotor is in the wrong position.

Post edited by: steell, at: 2007/12/24 17:13

Since I always remove the stock rotor and IC igniter ignition on any bike I own and install a new Dyna S, I am not sure about the stock rotor of the top of my head but if you install a Dyna S, and install the rotor with the magnet incorrectly, the symptoms will be exactly like described initially (having coil wires reversed). On the Dyna S rotor there is a small indentation that is the magnet. You need to put the #4 cylinder at TDC and the magnet needs to be pointed towards the 1&4 pickup. If you point it towards the 2&3 (very easy to do), it will fire 180 degrees out. Bike won't start and it will backfire through carbs.

kinda like changing out a automotive distributor; 180 degrees off is easy to do. How do I know? I did it on a 67 Buick I had and it did the exact same thing. There was so much flame out the carb, I could have roasted weinies over it:pinch:

Greetings, all.

Thanks for your help and suggestions, but alas they seem to have been to no avail. I have two KZ750N1 Spectres, and starting this afternoon they will be combined into one bike that will incorporate the best aspects of both. A fresh engine and powdercoated bracketry/wheels from one with the stretched frame, drivetrain, and forks from the other.

I have spent enough time on the ignition problems and am going to scrap the whole ignition system for an aftermarket setup on the new bike. As for the factory setup: It wins, it beat me, it gets trashed.

Thanks again.