Re: 200mv on the black/yellow wire to the power pack. Help please!!
Possibly I'm missing something in all of the above as I have a problem in reading posts that are all one paragraph which measure 3 or 6 inches in height or so, especially when they get into service manual specifics such as pin A to pin C etc etc. Probably just me (age) but I prefer the KISS method.<br /><br />That said..... Jquest, you say that your engine will not exceed 5000 rpm. Has it ever exceeded 5000 rpm on this same boat, and if so, has there been any repairs, improvements, additions made to the boat or engine between that 5000+ rpm time and now?<br /><br />If it's listed above, I've overlooked it. What is this engine (make, hp, year), and what is the boat make and length. Has the boat been trailered or does it sit in the water constantly which if being berthed, marine life could gather on the hull which would greatly affect the rig's performance.<br /><br />Hopefully you've had the timing checked, and also checked to see that the timer base under the flywheel isn't sticking. I'll assume that your mechanics have correctly saw to it that the compression and spark is as it should be.<br /><br />Compression = 100+psi and even on all cylinders. Spark = Jumps a 7/16" gap with a strong blue lightning like flame (SNAP!).<br /><br />Now.... The Black/Yellow wire (Yes Mike, that's the kill wire). The voltage measurement I speak of is to be taken with the Engine Not Running. Some of what I read above could be construed as the Engine Was Running on various tests.<br /><br />With the Engine Not Runing, key set to OFF, remove the black/yellow wire from the powerpack(s). Connect a voltmeter, set to it lowest reading, between the ENGINE WIRING HARNESS black/yellow wire and ground (Not at the powerpack!). There should be no reading.<br /><br />Turn the key to the ON position, Engine Not Running. There should still be no voltage reading.<br /><br />In either of the above instances, if a voltage reading is present, disconnect the large RED electrical plug at the engine. If the voltage reading persists, then obviously the problem is with the engine wiring harness.<br /><br />If, on the other hand, the voltage reading ceases to exist when the RED plug is disconnected, the problem (voltage bleed) would be in either the instrument cable or the ignition switch.<br /><br />Check the ignition switch by plugging the RED plug back together, then removing the black/yellow wire from the ignition switch. If the voltage ceases to exist, the switch is faulty. If the voltage persists, the instrument cable is faulty.<br /><br />Note that all of the above IS NOT to check for a rpm problem but rather a test designed to find why powerpacks continue to fail, one after another within a short period of time on the same engine. Any amount of DC voltage being applied to the black/yellow wire will destroy the powerpack.<br /><br />Pertaining to whatever voltage DC or AC which might be applied to the black/yellow wire At The Powerpack when the Engine Is Running, I have no idea, but it will be there and it is usually found to be quite shocking (grin).
