Thread subject: Whaler Central - Boston Whaler Boat Information and Photos :: Lower Unit Mountng Bolt

Posted by coopgraphic on 08/11/10 - 7:42 PM
#1

I have a new lower unit that I am installing and the furthest bolt back (under the rotating trim tab) needs to be longer to fit the newer style lower unit. The old bolts did not have any markings as to what grade they are. Its a 5/16 Stainless Steel bolt but not sure what grade. I am curious if anyone knows what grade bolt should be used. I'm not even sure if its truly for mounting or if its more for the anode but any help would be greatly appreciated. This is the one thing that is keeping me from putting the boat in for the weekend.

Edited by coopgraphic on 08/11/10 - 7:52 PM

Posted by John Fyke on 08/11/10 - 9:09 PM
#2

Are you saying you need the bolt for the anode?

Posted by coopgraphic on 08/12/10 - 3:41 AM
#3

It actually goes underneath where the adjustable trim tab is bolted on. It goes directly into the gearcase so I dont believe its for the anode.

Posted by CES on 08/12/10 - 3:47 AM
#4

When I'm unsure of what a part is, I go to www.boats.net and plug in the motors information and find out what the part is.

Posted by MW on 08/12/10 - 4:00 AM
#5

What Engine type ? You can bring the bolt to the dealer and tell him that you need a longer one. If it's an Evinrude, the engine/boat will run without the bolt (and trim tab) as long as the other bolt's are snugged up correctly (temporarily).

* Put some "Never sieze" ( $6 auto store) on the bolts before you put them back in, that way you can remove the lower unit again in the future without snapped bolts, new curse words, and a fight.

Edited by MW on 08/12/10 - 4:03 AM

Posted by coopgraphic on 08/12/10 - 4:10 AM
#6

It is an evinrude...1979 150. Any ideas as to what grade of stainless that bolt would be. I have access to stainless bolts (I am going to see what grade they are today). The old one has a smooth top so the normal grade markings are not present.