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89 Johnson 150GT No fire

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"This motor has 35 amp stator.

"This motor has 35 amp stator. Motor failed to start. Checked for spark,has none on all of the 6 cylinders. Don't think the charger has been working correctly. Tach has been intermitently dropping to zero for last 2 years. I swapped out the the power pack for a used one. Now have spark on 1,3,5 & 6 none on 2 & 4. Verified that coils are good by swapping them around. Ideas?"
 
"The tach and ignition are sep

"The tach and ignition are seperated as the tach takes the signal from the charge coils on the stator through the regulator and the ignition takes the power from the power coils on the stator.
First take off the fly wheel and inspect the stator for meltet insulation on the power coils. If dammaged change the stator. If ok, do an ohm test on both charge and power coils. You find the readings in the manual, but if any is shortened or open, change the stator. However I would not be surprised if You end up with a new power pack!"
 
"I'm leaning toward the po

"I'm leaning toward the power pack being bad. Removed flywheel and found no damage. Coils(3 sets)all are ~830 ohms. Also megged them to ground, result was good. Is this a fairly common problem with these motors? I read somewhere that the reason for charge coils melting is due to the regulator being bad and not providing a closed circuit for the large coil asociated with the battery. This in turn causes heat to build up in the stator assy and melt the smaller coils. What do you think? The Tach dropping to zero, is this a good indication the regulator is failing?"
 
"Sorry for being late with ans

"Sorry for being late with answer, but this site is at the moment not working as intended, we do not get any e-mail warnings so I had to do it manually.
Back to the topic.
Technically the charge coils and power coils are two separate systems. Power coils (two small) charges the power packs, the charge coils the regulator. Bad power packs (grounded) may overload the charge coils and make them melt. Shorted regulator may overheat the whole stator system included the power coils. As the tach takes the signal fron the regulator this is the 'normal' way of detecting a faulty regulator.
Normally if stator, power coils, fail there will be no spark at any cylinder, or if the coils are getting 'weak', spark may be missing sometimes but rarely on the same sylinder. It somewhat 'jumps' around."
 
"Installed a new powerpack but

"Installed a new powerpack but still have no fire. I'd say it's the Stator for sure now. Even though the Stator has no melted coils, all power coils read ~830 ohms and it produces pulses when viewed with a Fluke scopemeter. Any other ideas? I have had to replaced Stators twice in the last 6 years. Why does this happen?"
 
"What could be inteesting in Y

"What could be inteesting in Your case would be to take a voltage reading from the stator when crancking. If the Ohm reading is within the prescribed but the voltage below at crancking speed, this may indicate a weak flywheel magnetism. Unfortunately I have no manual and do not quite remember the required voltage, but it should be in the Seloc. You would need a peak voltmeter for this test."
 
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