coil on a 1974 mercury 650 with thunderbolt ignition!!!!

[hfd12]

i was wondering/ im not getting any spark so i looked at the coil on the side of the motor and its all cracked in different directions ? is it bad? thanks and is cold compression of 125,135,135 psi good as well? thanks

 

[Chris1956]

Re: coil on a 1974 mercury 650 with thunderbolt ignition!!!!

Cracking is usually death to a coil. Replacements are avail from CDI, Sierra etc. You have the big ugly red coil, right? The replacement will be a smaller black plastic coil with a metal cover.

 

[hfd12]

Re: coil on a 1974 mercury 650 with thunderbolt ignition!!!!

I have one ordered and should be here in a week. no its not a big red one its the black one with the metal cover, sop i should asume its been replaced already atleast once. what causes it to crack? thanks for ur info its greatly apprecitated

 

[Chris1956]

Re: coil on a 1974 mercury 650 with thunderbolt ignition!!!!

I am not certain what coil was on that motor. You can look at the picture on crowleymarine website, and likely tell, if you are interested.

I think the older coil was attached differently, then the replacement coil. The newer coils had three 5/16" bolts, arranged in triangle. How was your bolted on?

 

[emckelvy]

Re: coil on a 1974 mercury 650 with thunderbolt ignition!!!!

The 3-cyl motors came with the smaller coil. Cracked is bad!!!

 

[danimal69]

Re: coil on a 1974 mercury 650 with thunderbolt ignition!!!!

in 1974 the 650 3 cylinder came with a black coil