Thread subject: Whaler Central - Boston Whaler Boat Information and Photos :: Outboard bolts
Posted by rogerhoward on 09/01/10 - 9:51 AM
#1
I just picked up a new (old) motor for my 13'. I have two bolt holes intact from the previous motor that should line up fine, but I'm debating how many bolts I should need through the transom. Is four bolts total enough? My previous motor had 2 bolts through the transom, and another two which simply clamped to the transom, but this one is a bit bigger and has a simple mount plate with the standard hole pattern.
Also, my previous motor's mount had sufficient "lip" coming up and over the transom and back down, so that it could just sit on the transom without much concern for it falling off, whereas the new one has very little overhang - most of the weight of the motor will be sitting on the top or outside of the transom.
(4) 1/2" stainless bolts with locker nuts and large stainless washers on the interior of the transom, coated with plenty of 4200 as sealant?
Since the new motor is a good bit heavier than the old, I'm wondering if I should be using some kind of plate on the interior of the transom to better distribute the weight/stresses from the mounting bolts?
Posted by CES on 09/01/10 - 10:25 AM
#3
If your outboard motor mount has clamps on it, those will suffice for the upper mounting of your motor. Then you'd use two Stainless Steel through bolts for the bottom two holes.
Posted by John Fyke on 09/01/10 - 10:27 AM
#4
Roger, your project looks to be coming along nicely. Good job.
Posted by rogerhoward on 09/01/10 - 10:37 AM
#5
The new outboard doesn't have clamps...
So it looks like the top black holes line up with where I've already got holes... for the bottom, I guess I'll have to measure and see where these'll come out on the inside - worst case, I guess I'll be using lag bolts.
If lag bolts, would you recommend I use 4 lag bolts (plus the two at the top that go through the transom)?
This is on a 1976 13' Whaler, in case that matters.
Posted by rogerhoward on 09/01/10 - 10:45 AM
#6
John Fyke wrote:
Roger, your project looks to be coming along nicely. Good job.
Thanks - it's a lot further than the latest photos even... new NFB steering arrives today, so I'm ready to drop the new motor on, figure out the wiring harness connections, and rig up the throttle controls. I'm hoping to be on the water Saturday - provided I ditch work Friday!
Posted by John Fyke on 09/01/10 - 11:41 AM
#7
Go ahead and ditch. Work is over rated anyway.
Posted by John Fyke on 09/01/10 - 11:43 AM
#8
You haven't said what motor you will be mounting. My guess is if it is mounted right you will probrably be able to through bolt the bottom also.
Posted by tedious on 09/01/10 - 11:57 AM
#9
Roger, you should use 4 through-bolts - forget the lags. You don't need to worry about the "lip" overhanging the transom - in many cases the motor is lifted enough so that does nothing for you. Here's a link to the setup I am working on: http://www.whalercentral.com/forum/viewthread.php?thread_id=10837 and you'll see the lip is doing nothing for me - maybe I should hacksaw it off and save the weight!
Tim
Posted by Joe Kriz on 09/01/10 - 11:59 AM
#10
You shouldn't have any problems using the Standard BIA and 4 through bolts and drilling the red colored holes in the drawing.
That drawing is mostly for the 16/17' models so they are cautious when drilling the Yellow colored holes.
Just double check the bottom holes to make sure before you drill them.
This way you can use any engine in the future without any more drilling.
Edited by Joe Kriz on 09/01/10 - 12:01 PM
Posted by rogerhoward on 09/02/10 - 11:49 AM
#11
Thanks guys - I had to drill four new holes last night as the two old holes seemed to be lined up with the lower black holes and were positioned too low. New holes are clean and perfectly aligned, thanks to using a plywood template (clamped to engine, drilled, then clamped to transom and used as a guide). rather than trying to measure it perfectly. Mounting the motor tonight...
FWIW, the new motor is actually an old rebuild in great shape I picked up for a song - 1975 55hp Evinrude, a bit on the big side for a 13' but I don't think outrageously so... never seen salt water, just needs a repaint at some point - compression was awesome, runs great.
Posted by Joe Kriz on 09/02/10 - 12:08 PM
#12
Which holes did you actually drill?
The top 2 holes should be about 2 inches down from the top of the transom and then the other 2 holes should be 8 inches below those holes.
Let us know which colored holes you drilled so anyone coming after this will know what holes to drill for their 1972 13' models and later...
Black Upper Holes ?
Red Lower Holes ?
The above colored holes are the Standard BIA....