Better coil for Merc TB IV?
 

I ran into some ignition breakdown at engine speeds above 5200 RPM over the weekend and I thik it's probably due to the coil.

Any suggestions on a good replacement coil?

Thanks!

MSD Blaster High Vibration. Definatly!


Summit or Jegs would have the best price.

Eric

Checkmate,

Would that MSD be a good upgrade for any Thunderbolt IV?

well the factory coil is supposed to be rated at 18,000 volts... the blaster coil 40,000. I changed my wires , plugs , cap , rotor and coil. The cap had some nasties built up on it. Starts much better and accells better. Top end didnt change [ damnit]

I second that
MSD blaster High vibration coils
40,000 volt shock to your otherwise weak system.
total tune ups
Plugs, caps, rotors, coils and wires will definately make your engine more efficient
might not see any more rpm's but full tune ups and ect will increase your fuel economy by a little bit.
good choice, Jegs had them -- I got 2 for 80 bones for the pair
Jason

Isn't there a rev-limiter built into the Thunderbolt IV ignition? I recall it's supposed to be somewhere aroud 200 RPM over factory max RPM???

Might check into that one because it may be time for an aftermarket ignition or a different module with a higher rev limit?

There isn't a Rev limiter on the Mark IV ingnitions, only on the Mark V. I run up to 5400 RPM with my worked 454 Mag (470 hp) with the stock ignition. Just in the process of adding larger plug wires (8mm) and am going to get a MSD Coil. May go compete MSD next season.

Yes the MSD will work with any Thunderbolt IV or V system. I have it on the Thunderbolt V.

Scott is correct, there is no rev limter on T-IV systems. Your new MSD coil will bolt right on. The two wires(gray&purple, I think) go to the same posts that they were attatched to on the old coil. + and -.

Eric

My T-bolt IV does have a limiter. But not all do, so it is possible.

I forgot about yours Jerry. I wonder if it was used only on the HP motors.


Eric