'71 J-125 Ign Pulse Pack

[emckelvy]

Anyone have a good used one of these? Working on a motor that's not really worth dumping the price of a new box into. P/N: 398362.<br /><br />I was also wondering if there's any possibility of upgrading this old, cantankerous ign to something different or newer? I've got tons of Merc inline switchboxes that are as reliable as all getout; these can be used in a points application if wired correctly. I was thinking that maybe the trigger-type of ign could be converted back to the older-style dual-points under the distributor, then triggered off a Merc box.<br /><br />Or is there any other kind of power pack that will fire off the existing trigger signal?<br /><br />Anyhow, any thoughts or suggestions would be appreciated.<br /><br />If you've got a good used box, give me a holler at (anti-spam):<br /><br />eddymac246 -at- netscape.net<br /><br />Thanks.............ed

 

[karmrd]

Re: '71 J-125 Ign Pulse Pack

I have a '72 100hp Johnson with bad pulse pak. I am very interested in the answer to your questions.

 

[WillyBWright]

Re: '71 J-125 Ign Pulse Pack

The Merc switchbox won't fly. It feeds individual coils. Your system has one coil that produces spark directed by a distibutor. Plus yours works on battery power input wheras the switchboxes use over 200 volts of input.<br /><br />There was a guy several months ago that had his converted to conventional points ignition by some mechanic. I tried to get him on to explain how, but got no response.

 

[emckelvy]

Re: '71 J-125 Ign Pulse Pack

I wasn't referring to the ADI powerpacks, but the older switchboxes that were on the distributor models. If you jumper the correct terminals on the switchbox, you can trigger the box with a set of points.<br /><br />The older Hydroelectrics had a dual-points breaker plate, what I was thinking is that you could adapt this to the trigger-model V4, as long as everything bolts up, and you're able to actuate the points. <br /><br />I can't remember if those models had a points cam lobe built into the crankshaft, or had a slip-on lobe such as how the reluctor fits on the crankshaft (with 2 locator pins).<br /><br />Even if the Merc box wasn't suited to the application, any of the old car-CD igns that were triggered off points should work. But, if the later crank has no way to run a set of points, it's a show-stopper on that idea. For that matter, you should be able to do the same thing on any of the older 3-cylinder models (such as the 55hp) which have points under the distributor, and a CDI box.<br /><br />Anyway, the 125 is probably a moot point, it's got the squeaky crank bearings so not worth putting $300 in a box just to run it and find out the innards are shot. Just another old boat anchor now!!!!<br /><br />Thanks for the suggestions.........ed

 

[ledgefinder]

Re: '71 J-125 Ign Pulse Pack

Yes, all 1969-72 V4s have BOTH the cam on the crank (points) AND the two holes for the rotor (sensor) - so either style ignition will bolt on. <br /><br />In theory it is 100% possible to run a battery powered points/condensor/coil/ballast resistor ignition on these - like they ran on maybe 500 million automobiles. Check the archives 3-4 years ago for best discussion on this point. I have all the parts to try it in a 'junkyard dog special' 125 (tagged as an 85hp) if I can ever get around to it.

 

[R.Johnson]

Re: '71 J-125 Ign Pulse Pack

If you are going to expierment with a pak from an auto, here is another thing you may want, or have to try. They made two different rotor's to trigger the sensor on these engines, The difference being the width of the lobe. Some year's back, I talked with a man who was trying this very thing. He said to get it to work, he had to use the rotor with the narrow lobe's. He was working with a pak from a early to mid 70's ford. Keep in mind here that I never seen this engine, I'm just going by what he had to say at that time. The OMC pak put's out 250 + volts to the coil so maybe you can use this figure to compare to other pak's. Here are the figure's on the rotor's, phase 1, 1" tooth, 1/2" gap- phase 2, 1/2" tooth , 1" gap. If you can get your hand's on a Rapair catalog, they show a simple bench test to check the pak. This may save you some time when figureing out the wiring. It would be great if you can get this plan to fly. Keep us posted on what you find. Here is another thought, if you go to an auto salvage yard, you could look at other style pak's to compare. I would'nt think they could cost to much money.

 

[emckelvy]

Re: '71 J-125 Ign Pulse Pack

Ahh, I was wondering the diff between the Phase I and Phase II rotors. I saw in the replacement pak requirements where they said to use a Phase II rotor. Must be a 'dwell' type of thing, eh?<br /><br />I posted in the 85 HP ign string in more detail about using the Merc box, I bet it would work like a champ in this application.<br /><br />And if you used the Merc coil, you've got a matched set. The smaller (black) Merc coils used on the early-70's distributor inlines would be a lot easier to mount than the big, red ones used on older models. Electrically they're the same.<br /><br />So, my big question is, are the points on these V4's make-to-fire? Because if they are, the Merc box would be perfect. After you jumper out the trigger terminals, it fires every time you ground the remaining black terminal.<br /><br />You could mount it right where the OMC box sits by drilling 4 holes; then wire everything right to the terminals on the Merc box. The small Merc coil shouldn't be too hard to mount, either.<br /><br />Whaddya think??

 

[R.Johnson]

Re: '71 J-125 Ign Pulse Pack

The points fire on break.