Lower unit question

sparticus

Petty Officer 3rd Class
Joined
May 31, 2007
Messages
92
I know ....another lower unit question. I have all the bolts out of my 66 650 merc lower unit, except for one. I am an aircraft mechanic by trade and as such it pains me to see such crappy manuals out there for folks to use. All I lack to drop my lower unit is the bolt at the rear of the unit that holds the trim tab into place with the lower unit. Any one have a size on the bolt that does this? Its about 6" inside the hole and I can't for the life of me see that far into it because my glasses wont focus that close (it sucks getting old). I can see daylight all the way around the unit except for this place so I am reasonably certain that this is the part that is holding me up. Thanks for any help you can throw my way!
 

Laddies

Banned
Joined
Sep 10, 2004
Messages
12,218
Re: Lower unit question

It's a 5/16 allen srew and the bolt that holds the unit is under the tab and has to be removed. If you had bought a OEM manual you would be happier
 

sparticus

Petty Officer 3rd Class
Joined
May 31, 2007
Messages
92
Re: Lower unit question

Ok.....so lets see if I have this straight. There is a 5/16 allen screw that has to be removed so that the trim tab can be removed. This in turn will show me another bolt to finish removing the lower unit. Have I got it right? I agree that in retrospect a OEM manual would have been the way to go. I will have to invest in one. Thanks Laddies for the quick response.
 

sparticus

Petty Officer 3rd Class
Joined
May 31, 2007
Messages
92
Re: Lower unit question

Laddies....Thanks for the info on the 5/16" hex head bolts! It was spot on. Got the LU out, impeller changed and the LU reinstalled. Will be testing my handywork later on today. Hopefully it will all be good.
 
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