power pack or stator?

[hydrick]

how can i determine whether my power pack is bad or whether it's the stator.seems to me i should be able to bypass the power pack to see if there's fire, i just don't know which wires to jump.
this is an 87 vro johnson.
no fire at the moment.
thanks in advance

 

[jtexas]

Re: power pack or stator?

What horsepower?
First, check the emergency kill switch. 8)

Then disconnect the black/yellow kill wire from the powerpack and retest...if it fires, troubleshoot the kill circuit -- keyswitch, kill switch, wiring harness.

Still no fire, disconnect the rectifier from the stator and retest - if it fires replace the rectifier.

If you have a digital multimeter with a DVA adapter you can test for stator output to powerpack should be 150volts peak AC.

 

[hydrick]

Re: power pack or stator?

40 hp. no kill switch8)

when you say disconnect, i take you to mean i'll have to cut it. then resplice.?

is the rectifier the funky looking thing that favors a blinker switch and has the one red and three yellow wires connected to the grounding block and near the two coil packs?

thanks.

 

[jtexas]

Re: power pack or stator?

Rather than cut the wires, disconnect them where they plug in and pull (or push) that pin out of the plug.

Yup that's the rectifier.

 

[hydrick]

Re: power pack or stator?

admiral,
i'm not near the boat at the minute, but aren't there two or three yellow from the rectifier to the stator?disconnect all?

 

[jtexas]

Re: power pack or stator?

Yes, two yellow are AC from stator - these should be disconnected. The red to battery (for charging), and the other I think should have a gray tracer (tach sender). Anyway, any doubts its okay to disconnect 'em all.

Inspect all the wiring for corrosion, loose connections, old flaky or missing insulation.

 

[hydrick]

Re: power pack or stator?

you're a prince and a scholar.
thanks for your help.
sincerely,
ronnie

 

[hydrick]

Re: power pack or stator?

zero fire bypassing kill switch, and rectifier.
i don't have a dva adaptor.
would folks agree that a power pack is most likely the problem and a cheap try over stator and yanking flywheel?

 

[hydrick]

Re: power pack or stator?

i put on the new power pack last night and she fired up immediately.
thanks for your help.
sincerely,
ronnie

 

[imported_lorin]

Re: power pack or stator?

Just curious-why bother checking the rectifier. It has nothing to do with spark. You could stick a fork in it and you should still be able to get good spark.

 

[jtexas]

Re: power pack or stator?

more than one way for a rectifier to fail...and not all rectifier failures kill the ignition...but a shorted rectifier diode can provide a path to ground for the ignition...I couldn't prove it to ya from looking at the wiring diagram, but it's a step in the troubleshooting process...if you're sure the rectifiers good (battery's charging normally), you can skip it.

 

[imported_lorin]

Re: power pack or stator?

I guess I'd have to disagree. The charging system is totally separate from the ignition system. And having looked at many OMC service manuals I've never seen anything related to the rectifier mentioned in their trouble shooting guides of ignition systems. If you find anything of that sort in a service manual I'd be interested in seeing it.

 

[hydrick]

Re: power pack or stator?

since you're both back on the subject, and for my own piece of mind in the future, is it possible to check the stator without the ohm meter and dva adaptor?
for example, though archaic, could'nt you rig up a way to disconnect yellow wires at rectifier and place two spark plugs and spin engine to see if there's spark?

 

[ezeke]

Re: power pack or stator?

The Rapair troubleshooting guide tells one to disconnect the yellow rectifier wires at many steps in the troubleshooting process. They make the system so I would guess that they should know.

Copy to your browser without the quotation marks:

"http://rapair.com/LinkClick.aspx?link=downloads%2fTroubleshooting+Guide+2006.pdf&tabid=247&mid=789"

This is a large manual, so be patient if you download it.

 

[imported_lorin]

Re: power pack or stator?

Just because they tell you to disconnect the rectifier wires at whatever steps doesn't suggest that the rectifier is a possible cause of spark failure. Does it ever say, "If no spark-replace the rectifier"? I doubt it, and if it does, I'd like someone to explain the logic to me. Maybe there's some other reason to disconnect them-I don't know. Again, the wires going to and from the rectifier are in no place nor way connected to any of the wires of the ignition system. They have as much effect on spark as the wires going to the primer solenoid. In OMC manuals the rectifier is in "electrical system" section as it should be and there is no mention of it in the "ignition system" as ever being a possible cause of spark failure. And hydrick, no-that last idea wouldn't work.

 

[jtexas]

Re: power pack or stator?

No, it says "if it sparks with the rectifier disconnected, replace the rectifier".

I'm sure Rapair doesn't mind you disagreeing with them. If your ignition ever fails, just ignore that part of the advice.

 

[imported_lorin]

Re: power pack or stator?

This is news to me so my apologies and I shall cut myself a large slice of "humble pie." Still wondering how rectifier and ignition could be related and more curiously, why the OMC manuals don't mention this as a possibility in their trouble shooting guides.

 

[hydrick]

Re: power pack or stator?

i was thinking along the lines of edison and the light bulb,lol like the filament. as in power generated by the spinning flywheel,and resulting arc at the plug.

 

[jtexas]

Re: power pack or stator?

lorin that came out more smart-xxx than I meant...your point is good and I couldn't find the connection either...but not being an engineer I just accept it.

hydrick, it takes upwards of 10,000 volts to make the spark. You could probably use a regular voltmeter to measure AC coming off the stator to the powerpack...and get a voltage/no-voltage determination, but it wouldn't tell you what you need to know which is whether it is sufficient.

Someone here posted an idea about measuring the powerpack capacitor output with an oscilliscope.

And, Paul Moir provided this schematic for fabricating a DVA - it's just a full wave bridge rectifier with a smoothing capacitor. I haven't got around to trying it out yet. Set your DMM for DC volts and add 1.4 volts to your reading to compensate for voltage drop across the diodes.

 

[hydrick]

Re: power pack or stator?

so at 150 volts coming out of the stator i suppose it's the coil packs upping the voltage to 10,000 eh?