Re: Pertronix and the Merc 898/888.
I have an Ignitor II on my 888. I'm happy with it. I also dropped in a Pertronix flamethrower coil. As already said, bypass the resistance wire (tan from choke if I remember right) and go 12 volts to the coil. Drop it in, reset the timing, and go.
I do have a cut-out issue at max throttle, but I'm 95% sure it's an issue of insufficient voltage going to the coil due to an undersize power lead. I almost never run it that hard, so I haven't gotten around to fixing it.
If you have an old cap, cut a hole in the top right inboard of the #1 plug tower. Take a white paint pen and run a line down the lenght of the rotor top strap. Then fire it up and stick your timing light over the hole. You'll be able to see exactly where the rotor fires in relation to the #1 Cylinder stud.
I was having apparent ignition problems on my OMC 5.0 Ford. I did this and found that the ignitor was not firing until it was 3/4 of the way toward the next cap cylinder stud. This was using a Pertronix II, on a Prestolite dizzy, that came rivited to a new 'point' plate and had no allowance for adjustment.
Pertronix had absolutely no explanation for it so I had to elongate the mounting holes and rotate the plate to get the rotor to fire in front of the #1 cylinder lug. Then while I was at it, I knew from another Pertronix application on my Mustang, that there should be a .030 gap between the magnet ring and the ignitor. Mine was .090. So I had to pop the rivets and move the ignitor in toward the magnet ring.
To compound matters, and this was not the doing of Pertronix, it turned out that the rotor tip was running about .090 below the bottom edge of the cap cylinder lug. It was actually leaving a carbon arc on the sidewall of the cap. That is actually what drew my attention to this last issue. So I had to disassemble the distributor, and space up the distributor shaft to move the rotor tip up into the lug cutout area. Once I did that, I had no spark so I had to pop the rivets on the module again, make an aluminum spacer for the foot, apply some computer chip thermomastic and re-rivet the module so the sweet spot was once again in vertical alignment to the magnet ring.
The only reason I could come up with on the rotor height issue is that OEM caps are no longer available for that old prestolite. They are all aftermarket NAPA caps. I think that they were of incorrect dimensions compared to the OEM caps. You still do see those old (NOS) caps on ebay. I have tempted to get one and check that out because there is no other plausible explanation for it.
Damm pop's you ever going to get that old scow up and running..Its been two years now and your still not ready for the main event..
