1990 Johnson GT 150, stator or trigger issues?

[gonefishin485]

so over the weekend i bought this motor, 1990 Johnson GT 150 V6 with the 35 amp stator and 35 amp water cooled regulator/rectifier. i bought it from a guy who seemed genuine with the understanding he had the motor at a shop and ran out of money to fix it, so therefore he sold it. according to him, the shop put a new power pack, and 1 new coil and said it needed a new trigger. i noticed when i took the starter off to clean the commuter and brushes that the regulator rectifier wire that went to the starter solenoid had a cdi electronics tag on it, so im going to assume thats fairly new as well.

the previous owner was telling me the motor would run, then it wouldnt. he took it to the shop, the shop had it running and called him to pick it up, then called him to tell him it wasnt running again. it was an intermittent spark issue. when i got it home and on a stand, i did the obligatory spark test, and my results were on the port bank i had fire on the top and bottom cylinder, nothing on the middle cylinder, and nothing on the starboard bank. (however it is worth mentioning that during testing the plug boot and clip came off the middle cylinder plug wire and while holding the bare wire trying to jump a spark, it shocked the **** out of me) if i swapped the leads from the power pack from a firing cylinder to a non firing cylinder, i could get every coil to throw a hot blue spark.

after about an hour of messing with it, it lost spark altogether. so i dug out my clymers shop manual and ohm meter and started testing. from the two charge coil test points the manual claims i should have 985 ohms +or- 25 ohms on both sets of wire pairs. max ohms i was getting was in the 820 to 840 range. i would have tried testing the timer base, but in the manual it shows an isolated ground wire that needs to be disconnected to ohm the timer base, and for the life of me, i cant find that isolated ground wire.

so what are the chances its the stator? or could it be the trigger as he called it, but my research shows its called a timer base. i wouldnt mind replacing both parts but seeing as both parts are in the 300 to 400 dollar range, ideally id like to replace the bad one.

any thoughts?

 

[emdsapmgr]

Personally, I prefer measuring the timer base and stator by checking the cranking voltage outputs of both devices. You may want to go out to this website first: cdielectronics.com. They have a really excellent ignition troubleshooting guide for your engine. There are two measurements you are looking for on a cranking test: The stator should put out something like 150-400 volts. The timer base should put out something like 0.6 cranking volts. Both need to be measured by a special "peak reading" voltmeter. I consider this measurement more reliable than the ohmmeter. The guide will tell you which wire pairs to measure from. If both devices measure out to spec, then I'd be looking at the power pack. From a pure statistical basis the power pack fails the most. But I would not just pop for all that money, till I tested the other two components first. For other engine repairs: Ditch the Clymers or Sealok manuals and go with a factory service manual: outboardbooks.com

 

[gonefishin485]

So here's my results after doing that test. Ohms remain unchanged. 840ish on both the brown/brown yellow and brown/brown white and around 100 on the two orange wires.

Im assuming i did the dva test correctly, i connected each lead from my volt meter to those sets of wires respectively and my results were....nothing.

With my meter set to 200 volts dc, spinning the motor over, i got a few tenths of a volt here and there, but nothing on all three sets of wires. Most it read was .6 on some trys but nothing of any significance and nothing anywhere close to the 100 plus volts cdi's website claims it should have.

Thoughts?

 

[emdsapmgr]

Are you using a "peak reading" voltmeter? Sounds like you are reading DC volts.

 

[gonefishin485]

Im using a digital multimeter from the auto parts store, setting it to 200 volts dc, and spinning the motor over. Thats the only meter i have so thats all i can use.

 

[James R]

You need a digital to analogue converter between the stator and the meter. if you can solder electronic components and can get them you can build one real easy.

 

[emdsapmgr]

You can't diagnose the problem if you can't determine the cranking outputs. Maybe you can rent one at the local auto parts store..

 

[gonefishin485]

You can't diagnose the problem if you can't determine the cranking outputs.

Thats not entirely accurate, recently i had the same intermittent/no fire issue with a 1999 25 hp mercury. Used the ohm specs on cdi's website to determine my trigger was fine but stator was bad. Found someone with some used parts, their stator ohmed out in spec, and once i put it on my motor, the motor fired right up.

Im not saying one way is better than the other, im just saying that the DVA test isnt the only way to know.

What i was looking for was someone who has more experience with these motors than i have to say "yeah its most likely that stator" or someone to say "if this is all the equipment you have, test this like this"

So far does anyone else besides me think its the stator?

 

[gonefishin485]

Also, to add, i have a 1977 Johnson javelin 85. When i got it, it had crazy intermittent spark here and there, broke out the manual, tested the ohms on everything i could to find out it had a burnt up power pack. Replaced the single power pack with dual power packs off a newer 115. Its not that i dont know what im doing, its behind 400 plus dollars for each part that could be bad under the flywheel, id like someone that has dealt with this before to tell me if im on the right path or not.

 

[Faztbullet]

id like someone that has dealt with this before to tell me if im on the right path or not.

As posted earlier you need the DVA adapter to properly test you outputs. These can be Googled and purchased or get the plans and build yourself.But from experience and problems your posting it sounds like the timer base. I see this at least 2-3 times a year and always on a V-6.

 

[gonefishin485]

As posted earlier you need the DVA adapter to properly test you outputs. These can be Googled and purchased or get the plans and build yourself.But from experience and problems your posting it sounds like the timer base. I see this at least 2-3 times a year and always on a V-6.

I think ive seen you around on scream and fly, you thinking the stator ohm are close enough and its just the timer base on these that have problems?

The guy i got it from said the shop told him trigger, which to me means timer base, but with the low stator ohms im second guessing him and myself.

 

[gonefishin485]

And for what its worth im using one of the red cen tech volt ohm meters from harbor freight

 

[gonefishin485]

Im currently hunting for a dva adapter, is there any way to test dva with a multimeter without the adapter? Even with a big fancy meter?

 

[Faztbullet]

Here.....
https://www.amazon.com/Electronic-S...F8&qid=1470441922&sr=8-1&keywords=dva+adapter

 

[gonefishin485]

Yeah ive been looking for one locally here in baton rouge, Louisiana, but no such luck. Can a high end volt meter read dva?

 

[gonefishin485]

ok, ill make a long story short, my mechanic uncle lent me an analog voltmeter and while changing the battery i noticed it had a 600v capacitor between two of the lead plugs. if you look up what a dva meter is, all it is, is a capacitor that stores voltage long enough for a digital meter to read it (more or less) anyway, so i connected the leads to the voltmeter, set it to ac volts, spun the motor over and i read ac voltage on both sets of brown wires, and the two orange wires.

so does this eliminate the stator as the trouble maker?