1977 1150 Coil Replacement Options

[kck8385]

I need to replace the coil on my 1977 Merc 1150. The current Merc number is 332-4985T 2. I can not find a Sierra coil that crosses with that number. Sierra 18-5186 crosses with Merc 339- numbers. Has anyone used the Sierra 18-5186 on an inline 6 motor? If not I'll bit the bullet and purchase the OEM.

Thanks,
Kevin

 

[Chris1956]

Sierra should make a coil for your motor. You need to look a bit more.

Are you sure the coil is bad? They last a real long time....

 

[kck8385]

Chris,

I ended up calling Sierra's technical department yesterday and was told they do not make a coil that crosses with mine. He looked up the Mercury number as well as my motor and said it was a no go. I ended up buying the Mercury coil. The Sierra number I gave above looks just like it but he said it was not a replacement for mine.

My coil readings were bad and it is cracked. I had the cowl off Sunday while it was idling in a tub and I guess the wind was blowing just right because I heard a random electrical clicking noise. When it happened 3 or 4 clicks in a row the motor would stumble. I thought it was coming from the coil area so I pulled it and found what you see in the pictures. The magnet is cracked all over. The triangular piece fell out when I pulled the rubber off. As you can see the plastic above the magnet is cracked also.

I will update my previous posts if this solves my 2 year long random electrical shutting off issue and more recent bogging at high RPM's.

Thanks,
Kevin

 

[Chris1956]

OK, well you got the defective coil. It had to happen to someone.

If memory serves me, Sierra did make a coil some years ago. Maybe they discontinued it. The ;last distributor Merc was manufactured in 1979, and the phase out of the distributor ign was well underway by 1976, in the inline 4 cylinder models.

Glad you found that issue. I new coil should surely help with your issue,

BTW CDI Electronics still makes ign components for your motor.

 

[kck8385]

Yea I seem go be lucky that way. Thanks for the help Chris.

Kevin

 

[jimmbo]

I wonder if copious amounts of non conducting epoxy would fix a cracked coil?