Electrical Please Help

canadianguy

Cadet
Joined
May 30, 2004
Messages
21
HI all<br /><br />Yes I'm back ! I really need help in figuring out this electrical problem , as the mechanics are getting flustered , and can't figure it out .<br /><br />I have a '79 , 115 h.p. outboard moter , 2 stroke . I had it rebuilt this summer ( took them 7 weeks grrrrrrrr ! ) Anyways , my first day out after the long wait , the moter crapped out again . Just before I had the rebuild , I put on a new power pack as one side kept dying out . They figured this would solve the problem .<br /><br />Now after aprox 2 hours of running the motor it acted up again . The new power pack is shot . Can any of you smart fellows , tell me what would keep killing the power pack ? The mechanics say that they have tested everything and they can't figure out what's doing this .<br /><br />I really hope one of you can tell me something to tell them to check out , as I have no clue , and neither do they . Thank you sooooo much in advance . <br /><br />The fishing is getting really good up here in B.C. I want to go play !!!
 

marinemech

Petty Officer 1st Class
Joined
Aug 12, 2004
Messages
250
Re: Electrical Please Help

3 things come to mind<br />1 the diode in the other pack may be bad if you still have spark on all 4 cylinders?? try number flywheel 1 2 3 and 4 at tdc check with a timing light to see if any cylinders are cross firing<br />2 the timerbase may be the culprit<br />3 try disconnecting the black yellow wire from pack(S) see if normal spar returns notr you will not be able to stop motor if it starts<br />good luck
 

R.Johnson

Rear Admiral
Joined
Sep 24, 2003
Messages
4,446
Re: Electrical Please Help

The power-paks on this system have a blocking diode to keep each pak from interfereing with the other. To check the diode, disconnect the 4 wire connector between pak & sensor base. At the connector from pak, connect an ohm meter between white, and yellow-black wire, and note the reading. Reverse the leads from ohm meter, and again note the reading. You should get a reading on the meter in one direction, but not the other. If you get a zero, or high reading in both directions, the diode is bad. The best way, and by far the most simple is to trouble shoot this system with a peak reading volt meter. The shop that rebuilt your engine should have one. If all test's well in the system, but keep blowing the same pak, ( that is with all solid ground connections) replace the coil, (coils) to that pak.
 

canadianguy

Cadet
Joined
May 30, 2004
Messages
21
Re: Electrical Please Help

O.K. I printed off these helpfull bits of information , and will take them down to the marina tomorrow , and give them to the " pros " .<br /><br />Hopefully these are things they haven't tried , and will get me fixed up . I will keep yas posted .<br /><br />Thank you marinemech , and R.Johnson for your speedy reply .
 

Paul Moir

Admiral
Joined
Nov 5, 2002
Messages
6,847
Re: Electrical Please Help

I just wanted to add a small note about R.Johnson's post. For testing the diode, he gave you the proper test procedure for an analog ohm meter. If you do the same test with a digital meter, the diode will appear open. When using a digital meter, you must use the 'Diode Check' function, which may be represented by an icon like this:
Code:
-|<-
Using that function, the diode should test under 1v in one direction (normally 0.5v to 0.7v), and offscale in the other direction.<br />I know that this isn't important to Guy, since he's taking his engine to professionals who know how to test diodes properly, but for the common man who may be ignorant of proper testing procedures, cheap digital meters are quickly replacing cheap analog ones in most people's toolboxes. <br />I've noticed no outboard manuals have yet changed their suggested procedures to reflect modern technology...
 

R.Johnson

Rear Admiral
Joined
Sep 24, 2003
Messages
4,446
Re: Electrical Please Help

Paul: Thanks for the input here. I still use my old Steven's analog meter for this test, and just tend to think of it. That was a good point about the service manual's, and digital meters
 

Stumpys

Petty Officer 1st Class
Joined
Jun 14, 2004
Messages
268
Re: Electrical Please Help

Excellent point Paul! Some digital meters will also have a diode fuction that beeps when the diode is biased. On any meter, is should read 5 to 7 volts when you bias the diode, and infinite when you reverse the leads on the anode/cathode.
 

Joe Reeves

Supreme Mariner
Joined
Feb 24, 2002
Messages
13,262
Re: Electrical Please Help

Remove the "black/yellow" wire from the affected powerpack. Turn the key to the RUN position (Engine Not Running). Connect a volt meter to that black/yellow wire, and of course the other end of the meter to a powerhead ground.<br /><br />Observe the meter closely. There should be absolutely NOT the slightest movement which would indicate even a microvolt at that black/yellow wire. If the slightest voltage reading exists, there is either a short in the wiring harness or the ignition switch is faulty (usually the switch).<br /><br />The slightest amount of voltage being applied to that black/yellow wire will destroy the pack. Having dual powerpacks, one would think that both packs would be destroyed, however weird things do happen and this is worth checking.
 
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