johnson 70hp 1992 stator testing - slight misfire

Hi, I'm in the UK and have a 1992 70hp johnson with a slight misfire and down on power. Checked the stator charge coil with an electrical meter as per workshop manual.

I disconnected the 5 pin plug and did the following checks;

Tested terminal A (brown lead) got a reading of 56v when cranking.
Tested terminal B (brown/yellow lead) got a reading of 76v when cranking.

Manual says voltage present here indicates that the stator/charge coil was shorted to ground. Not good.

Then checked output whilst cranking on terminals B (red meter test lead) and terminal A (black meter test lead) got 213v manual says should be minimum of 250v. So not good.

Resistance check across term A and term B shows 841 ohms which is ok.

So I bought another secondhand stator part number 584560 from a know good running engine, fitted it but misfire (very slight) remains, so i then perform the same checks as above and get more or less EXACTLY the same readings! With voltage showing down A and B terminals.

So my question is it correct / normal to see voltage down the terminals A and B ?

Any advice greatly appreciated.

I would do a compression test on the motor.-----------Then run with a timing light on each cylinder ( to full throttle while on the water ) to check how ignition performs.-------Use the timing light as a " poor man's scope " so to speak.---------Thereis a need to find out if it is an ignition miss or something else.

thanks for your reply. motor is just rebuilt 3 rebores and 3 new pistons, compression 150 psi. have done this with my timing light in my large test tank to WOT. spark test is jumping in excess of 7/16" but is not "fat" or blue. its very thin and gold colour. when tested on a loose spark plug its not the big fat blue spark i usuly see on other motors. timing light did not show any issues at miss point. Also i just dont understand why i cant see about 150 v at the primary coil connect only about 7v, but yet it runs and revs up?

That is all wonderful information that was not mentioned in your first post.----------I think you will need to do some further trouble shooting.

Thanks I will check all grounds and wiring.

I just quickly rigged up 2 defo engine ground using jumper leads, but problem remained.

But my question still remains if anyone can help....Is the statement in my SOLEC manual correct that says

"there should no voltage showing between A to ground and B to ground when cranking". Because I am still showing 56v and 76v as in my first post.

Yes I checked out the rectifier/regulator. Even though I was happy with I have fitted another one just in case, but no change. The CDI web site suggests disconnecting the unit I tried this at first.

The thing thats confusing me is when I crank over with the 5 pin stator plug not connected, I get 213v, but when I do a running check (made a modified plug to allow me to tap into the 5 wires) I can only get about 7v. So how can it actual run with such low voltage?

When you are testing your stator are you using a or dva adapter to your multimeter ?

no i have not got a DVA adaptor, just got peak hold on multimeter.