1968-64 mercury, 3.9 single.......

[G-loomis]

I have just got this motor from a buddy of mine who does not want to fix it, I will try though, my question is can I get a new thing where the spark plug goes in, ( I got a pic). maybe someone can rethread it,

my other question is what kind of spark plug do I put in there,

I am also repainting the cowling,

hope someone can help THANKS BRAD

 

[AMD Rules]

Re: 1968-64 mercury, 3.9 single.......

Unfortunately the broken part is the top of the cylinder cavity itself, where the spark plug threads in. It is not repairable. Your only option for that motor would be to replace the block itself.

What is the condition of the rest of the motor? Have you taken the lower unit off yet to inspect the drive and shift shafts? Very common to see them corroded (carbon steel) on these 3.9hp motors.

 

[AMD Rules]

Re: 1968-64 mercury, 3.9 single.......

Hard to see in this pic of my 3.9hp, but the drive shaft and shift shaft are corroded badly.... missing a lot of metal and probably leaking a ton of water from the pump. I have another lower unit just like it, in the same condition.