Coil Question

[dfski]

I have a question after reading a couple of recent threads but didn’t want to threadjack. My boat has a 351HO with the original OEM EI, similar to the picture below, along with the original coil. As recommended by Waterlogged and others, I’m considering replacing the module with a PNX-91589 EI module. However, in the meantime can I replace my original coil with a Flame-Thrower II Ignition Coil and would that be an improvement?

[stuartmcnair]

I just went through this with replacing my coil. Asked a question but never got an answer. Interested to know why you would change the EI module as I have the same setup.

[Miss Rita]

However, in the meantime can I replace my original coil with a Flame-Thrower II Ignition Coil and would that be an improvement?

I had drivability problems two years ago with the 351HO in my '92 PS205. I was thinking along the same lines as you, thought a new coil would be a cheap fix, so I put in a new FlameThrower II in July 2018 for $45. It didn't show any noticeable improvement. Two months later the ignition module quit suddenly, and the mechanic said my new, two-month-old FlameThrower was bad as well.

Long story short, I have a new ignition module, another new coil (different brand) and it runs great. It starts at the turn of the key, has a ferocious hole shot, and a GPS-verified top speed of 42 mph at almost 5000 feet altitude.

[waterlogged882]

I just went through this with replacing my coil. Asked a question but never got an answer. Interested to know why you would change the EI module as I have the same setup.

Not to speak for the gentleman, but I can attest the OEM EI modules go weak after years of use or time. Not sure which. I have changed out the entire module to the newer style with the FT-II coil. Makes for a good combination and a noticeably refreshed ignition system.

The one in the above photograph is definitely OEM 92. From what little I Know, I am going t o step out on a limb and say no (unsubstantiated). I typically replace the ignition as a combination of the two. I have not done only a new and hotter coilf for the OEM EI which had an OEM 10K volt coil, where the FT-II us upwards of 40k Volts output. I'd error on the safe side and install the combination pair.

.

[dfski]

Thank you for your responses. Several years ago I replaced the carb and it is running well. Cold starts, immediate restarts, acceleration, and WOT are great. However, if we sit for say 15 to 30 minutes or more it needs a throttle pump and sometimes a higher idle to start. Maybe that’s normal or I just need to slightly increase my idle speed. But having read much of the advice here, I’ve come to the conclusion that I may be on borrowed time with my EI module and coil. Since, I hate to mess with something that’s working I thought maybe I’d just replace the coil and see if that helps. Guess I’ll just order the PNX-91589 EI module and Flame-Thrower II Ignition Coil.