Dropping the lower unit on a 1961 Mercury 400

[DeepCMark58A]

Did my research to change out the impeller and started in what I found was different than what I have seen diagrammed. There were two nuts of the sides and a bolt going up the middle. I discovered another fluted bolt up in the exhaust. Weird thing is it isn't a normal bolt it has some kind of weird torx kind of head. Anybody know what the pattern is called and the size, I can not find this style of bolt in any diagram.

 

[jimmbo]

Looks like a 12 point bolt

 

[racerone]

On my white Mercury motors that has been an allen head screw.-----5/16" is the size if I recall.

 

[DeepCMark58A]

On my white Mercury motors that has been an allen head screw.-----5/16" is the size if I recall.

That is what I had read that it was an allen head screw, not the case on this one.

 

[racerone]

Is it all rusted out ?-----Stainless replacement of original ?

 

[DeepCMark58A]

Not rusted out the motor is very clean.

 

[racerone]

Drill the head off or weld a nut on it.---Should be an easy thing to solve this " problem "

 

[DeepCMark58A]

Drill the head off or weld a nut on it.---Should be an easy thing to solve this " problem "

No reason to drill it out, or weld anything, just wondered if this was a possible mercury piece of hardware to see if the size was known to accurately purchase the proper tool.

 

[Chinewalker]

The original allen head bolts were not stainless and have been known to corrode. It looks like someone replaced it with a 12-point head bolt. Find the correct socket and wrench it on outta there. If I had to guess, it would be 7/16"

 

[DeepCMark58A]

Grabbed a 12 point socket, hopefully that will work.

 

[DeepCMark58A]

The original allen head bolts were not stainless and have been known to corrode. It looks like someone replaced it with a 12-point head bolt. Find the correct socket and wrench it on outta there. If I had to guess, it would be 7/16"

Funny how well the right tool for the job works so well. Then again I should have known things went to well. I dropped the lower unit and discovered the splines on the upper shaft are a little boggered up.

 

[DeepCMark58A]

Decision time do I try to find a new shaft or a lower unit? makes me wonder what the receiving end of that shaft looks like.

 

[Chinewalker]

Long or short shaft? I may have a driveshaft... Drop me a PM.

 

[DeepCMark58A]

I did finally manage to find a "new" used drive shaft that appears to be in pretty good condition, good compared to some of the others that were available.