Mercruiser 470 ignition coil

[jabfd]

Hi guys well on sat my coil let go it only last a year and half cheap coil from napa what is a good coil to replace it with . Iam still running points

 

[achris]

OEM...

 

[jabfd]

is that the best option i saw some one using a flametrower but not sure if there were still using points

 

[Eric 3.7LX Alpha 1]

What do you have for voltage to the coil on the (+) terminal while the key is in the "run" position? It should be powered thru a resistance wire. I believe full voltage to the (+) on the coil can shorten point life and possible cause more heat to the coil also causing shorter life.

To test red test lead on the (+) terminal the black lead on a good ground not the (-) terminal.

 

[Capt. Click]

The OLE Fire It Up. Hey, here is what I did when I needed to replace my coil. I still run points. If I need points and when I replaced my coil I went an auto parts store and told them I wanted a coil for a 1974 Ford Pinto. I have had no problems what so ever with these parts. Sounds like that is what you may have done. Motor runs great with a quick start up. I have a spare coil a carry as part of my on the water repair kit. "GET'EM OFF THE BOTTOM"

 

[jabfd]

eric when i checked the voltage it was around 10 volts i still have the purple wire resitance wire hooked up looks original. the coil i had on from napa is dead after a year and half. i got towed on sat didnt know what it was and with wife and two year old on board i didnt bother. yesterday i put new point and condeser still it did not start i put my old coil back on that i keeped and it started but my problem i had before i changed it came back after 45 min run it starts to skip a little but always gets me home. just want to know if somebody has a good coil that maybe better then oem or napa. i herd of flametrower but not sure if thats a good way to go also if i get the flametrower can the same coil be used for points and later used for the conversion to electronic ignition. Not sure if thats a good chance for this engine just thinking about future upgrades thanks again jeff

 

[achris]

ok.. There seems to be some confusion around the voltage to a coil with a resistive wire.. I'll try to clear it up.
Understand how the circuit works. The power to the coil is supplied via a resistive wire, with a resistance of slightly less than the coil (assuming a pure resistance here, not including reluctance or inductive 'resistance') when you check the voltage on the + of the coil you will get a completely different reading depending on whether the points are open or closed. If the points are open you will read full battery voltage, because the 'resistance' between the coil positive and ground is finitely greater than the resistance between battery positive and the coil +. It's a simple voltage divider circuit. So, whenever the voltage on the coil + is to be measured the point MUST be closed, or you'll get the wrong indication.

Hope this helps (somebody)...

Chris.....