Powerpack Swap to GM Ignition is it possible?

[rodbolt]

Re: Powerpack Swap to GM Ignition is it possible?

in the above diagram the "kill " wire is #1 through the 1/2 watt resistor. the charge coils are connected to a full wave rectifier that is also connected to a crude voltage regulator by the two zeners and the SCR connected to the full wave rectifier.<br /> the full wave or bridge rectifier will make the + and - parts of a sine wave into all = or all - "DC' Voltage depending on design. remember a capacitor will store DC and pass AC. the diode above the kill wire junction prevents a reverse current that would damage the rectifier and prevent the cap from discharging into the rectifier.<br /> if you draw or copy 4 of those diagrams and cycle them it will make sesnse. remember when one input to the rectifier is positive the other is negative.then as the magnet continures past the charge coil it reverses with the same potentials of oppostie polarity.<br /> that difference in potential is what makes electrons move, they are lazy like me and must be forced to move

 

[Vigilante]

Re: Powerpack Swap to GM Ignition is it possible?

Just for the record the engine is a '73 85hp johnny.<br />OK I'm conforming to the OCM design (kinda outta charictor for me),however, The DVA from my stator is 75v and 0v connected to the PP. The sensor coil is a 0v connected or not it's almost as if the whole system is fryed. Incidentally is the '72-'73 65hp PP compatable with the '74-'79 85hp the 85hp PPs seem to be out of stock. The 65hp "looks" the same and are ten bucks less.

 

[Vigilante]

Re: Powerpack Swap to GM Ignition is it possible?

Oops I ment '73 85hp Evin

 

[rodbolt]

Re: Powerpack Swap to GM Ignition is it possible?

well the 65 is a 3 cyl so it is one output shy of your V4.<br /> are your tests loaded or unloaded? spark plugs in or out?<br /> also occasionally for some reason the sensor air gap goes off, dont ask me how but it does.<br /> rapair makes an airgap tool.<br /> rapair also offers a lot of the electronics plus a comprehensive testing guide for that system.

 

[Vigilante]

Re: Powerpack Swap to GM Ignition is it possible?

Spark plugs were in<br />Whats the potocal for air gap adjustments

 

[ezeke]

Re: Powerpack Swap to GM Ignition is it possible?

Compatible powerpacks are 1973-1976 85HP,115HP,135HP and 1977 85HP and 115HP.<br /><br />Run spark test with all plugs out. Needs 300 RPM.<br /><br />Plugs out allows for deficiencies in battery power.

 

[McGR]

Re: Powerpack Swap to GM Ignition is it possible?

Vigilante - I think one concept you may be struggling with is the fact that these motors use magneto ignition. In a magneto ignition system, the ignition system is completely independent from the starting & charging systems. The rectifier and stator merely keep the battery charged for starting purposes, they have no bearing on ignition purposes (unless of course the starting system is not cranking sufficiently fast). Similar to a pull start lawnmower, the ignition system on these motors does not require any external power source. Once the flywheel gets spinning sufficiently, induced voltages take care of the rest. This is a good feature for many outboards, because if you accidentally run down your battery, the motor can still be pull started (not that it would be all that easy with an old V4).<br /><br />Ideally, you wold have a specialized tester for this ignition system. Ofent this is beyond the means of the typical weekend warrior. All is not lost however, as there are some basic static resistance measurements that will often suffice in troubleshooting these systems. Here's what I would do:<br /><br />1. Measure the sensor coils. First remove the sensor leads from the power pack. Measure the resistance across the leads. The measurement should be 8.5 +/- 2.0 Ohms. Then, keep one meter lead attached to either of the sensor coil terminals. Touch the other meter probe to the block (obviously on a non-painted surface). You should get infinite resistance. Any resistance present indicates a problem.<br /><br />2. Measure the charge coils. Placing an Ohmmeter across the charge coil leads (brown/ brown yellow wires). You should measure 630 +/- 50 Ohms. Again, keep one lead attached to the meter and check for isolation from ground. Any resistance is a problem.<br /><br />3. Measure the ignition coils. The primary sides of the coils should measure 1.2 Ohms maximum. The secondary should measure 3000 Ohms maximum. Isolation from ground should only be tested once the primary winding that connects to ground is first disconnected.<br /><br />Now, these tests are static/ high impedance tests. However, under dynamic conditions occasionally such a test will fall short. So, they are not absolutely fool proof. However, I would be inclined to say they are 95%+ accurate. If you perform these measurements and everything checks out. I'd be looking at the power pack.

 

[McGR]

Re: Powerpack Swap to GM Ignition is it possible?

VG the 65hp is a three cylinder power pack... won't work.

 

[McGR]

Re: Powerpack Swap to GM Ignition is it possible?

Sorry didn't see your follow up regarding the hp. I believe the '72 is very different but the '73 is quite similar to the '76 packs. So, I'm perplexed that someone is combining these two years. Are you trying to buy one locally or on line? There are quite a few places to purchase these on line (including Iboats I believe.)I'm sure someone must have the correct ones in stock.

 

[ezeke]

Re: Powerpack Swap to GM Ignition is it possible?

1972 and 1973 V4 models have almost nothing in common.<br /><br />Iboat's Sierra 18-5753 is out of stock, but Ishopmarine.com has them as well as the OMC powerpack.<br /><br />The OMC/BRP powerpacks that work are numbers 0581311, 0581731, 0581895, and 0582056

 

[Vigilante]

Re: Powerpack Swap to GM Ignition is it possible?

I have a semi embarrasing story about why I have the '56-'72 shop manual rather than the '73. My '69 jonny 100 sits at the bottom of the river via a rotted transom and over zealous boating activity. Thanks ezeke for the compatibility update. I'll be be back out to the boat to do some more Volt Meter checking. My email is forwarded to my cell phone so I know when you've responded. I can't begin to express my apprication for everyones input.

 

[Vigilante]

Re: Powerpack Swap to GM Ignition is it possible?

A new PPk from Ishopmarine.com worked well for about an hour until it blew. Thanks to a very curious boater I needed only to paddle 1/2 way back (water skis worked well here). I did notice the warnings on the PPk that motioned I should look for the problem rather than the result of the problem. They mentioned a bad rectifier being a problem, however, according to all these diagrams I’ve been studding these are 2 separate systems. It kind of defies logic this would be a problem yet it made the list of things known to blowout their product; I’d think they’d know. Consequentially I’m being allured back to my initial brain child of the GM ignition swap. I drew a rough schematic of it and not sure how to post it. I’d like to see your opinions and feasibility forecast percentages

 

[rickdb1boat]

Re: Powerpack Swap to GM Ignition is it possible?

Hi Vigilante <br />Sorry to hear about the powerpack. And I doubt the rectifier would have been the cause. As for the pics, you will need to host them at a site and then copy the url of the pic and post it here. photobucket.com works well and is free. When you reply, just click on the "Image" button below and paste the url of the pic. It will then show up in your post.

 

[Vigilante]

Re: Powerpack Swap to GM Ignition is it possible?

This is my schematic it's probebly tiny 'cause I saved it wrong itr's almost to simple but of course the best ideas ussually are very simple