tango13
Petty Officer 3rd Class
- Joined
- Mar 10, 2015
- Messages
- 75
1995 7.4 Merc/Thunderbolt Ignition
S/N OF557755
Started the "tune up" process last spring by changing ignition wires and ignition sensor, and I'm going to finish up this fall by changing the cap & rotor. I know coils "never fail" but I'm going to remove mine to clean connections as my coil sits on the back of my block and conveniently sits right below the seam between my hood and transom, therefor i get lots of moisture dripping down. So much that the ignition wire between my coil and distributor was so corroded on the coil side that I had to remove with pliers. I figured if I'm gonna pull it and clean it up, I may as well just replace so I know where I'm at since I'm already doing the rest - blame it on my OCD, I like keeping stuff fresh.
Now the problem I have is that the Merc coil is in$anely expen$ive since Ill have to order from the states in USD (I'm in Canada) + shipping + duty, when I can just throw on a aftermarket for half the price or less from good ol' amazon.
So my question is, what aftermarket coil can I replace with? I believe the Merc # I need is 8M0079202, and my aftermarket options are MSD# 8222/8202 or Pertronix 45011. I didnt bother with the Sierra # as it also would have to come from the USA. I know the merc spec needs to be in that 0.7ish ohm primary area, 9-11k secondary. The MSD lists as 0.7 primary 4.5k secondary resistance, and the Pertronix just lists 0.6ohms primary and no secondary, so I'm a little cautious with this as I don't want to hurt the TB ignition system. Is the secondary resistance going to be an issue with these?
And yes Ill be making a "water cover" for the coil going forward...
Thanks in advance
S/N OF557755
Started the "tune up" process last spring by changing ignition wires and ignition sensor, and I'm going to finish up this fall by changing the cap & rotor. I know coils "never fail" but I'm going to remove mine to clean connections as my coil sits on the back of my block and conveniently sits right below the seam between my hood and transom, therefor i get lots of moisture dripping down. So much that the ignition wire between my coil and distributor was so corroded on the coil side that I had to remove with pliers. I figured if I'm gonna pull it and clean it up, I may as well just replace so I know where I'm at since I'm already doing the rest - blame it on my OCD, I like keeping stuff fresh.
Now the problem I have is that the Merc coil is in$anely expen$ive since Ill have to order from the states in USD (I'm in Canada) + shipping + duty, when I can just throw on a aftermarket for half the price or less from good ol' amazon.
So my question is, what aftermarket coil can I replace with? I believe the Merc # I need is 8M0079202, and my aftermarket options are MSD# 8222/8202 or Pertronix 45011. I didnt bother with the Sierra # as it also would have to come from the USA. I know the merc spec needs to be in that 0.7ish ohm primary area, 9-11k secondary. The MSD lists as 0.7 primary 4.5k secondary resistance, and the Pertronix just lists 0.6ohms primary and no secondary, so I'm a little cautious with this as I don't want to hurt the TB ignition system. Is the secondary resistance going to be an issue with these?
And yes Ill be making a "water cover" for the coil going forward...
Thanks in advance
