Question on Mounting New Outboard

[ERock82]

This post may sound like I'm being a bit picky but I just want to get things right.

I am putting on new transom trim for when I get a new outboard. I'm going to use a stainless steel angle that I will buy online. The trim that was original that cracked was 1/16" thick X 1.25" sides and was plastic or hard vinyl.

I found 2 possible items online:

1.) 1" sides at 1/16" thick

or

2.) 1.25" sides at 1/8" thick

How important is the thickness of the trim? I am worried that if I used the 1/8" thick then the new motor will be off by 1/16" from all of the mounting bolt holes.

I definitely DO NOT want to mess that up!

I am thinking to be safe I should use the 1/16" thick but I want the 1.25" sides.

Is mounting bolt height often an issue when repowering, regardless of the trim thickness? I know that if you stick with the same brand motor the bolt holes will usually be identical but height on transom seems like a different story as the mounting bracket thickness would have to be the same.

Any thoughts?

 

[Frank Acampora]

It really depends upon the height at which you mount the new engine: If the new engine needs to be mounted higher than the old one, OR if the old engine was mounted above the transom, then thickness of the trim is immaterial. If the new engine is going to be mounted at the same height as the old one and sitting on the transom, then thickness is a consideration and yes, with thicker trim, if the old engine was sitting directly on it, you will need to re-drill the mounting holes.

You really need to test fit the new engine for correct height of the anti-ventilation plate before buying the stainless.

 

[smokeonthewater]

1/16" isn't likely to make any difference.

If in doubt test fit the motor first.

Most likely the motor will be a couple inches above the transom anyhow.

 

[ERock82]

The old motor was mounted directly on top of the transom. I think I'm just going to go with the 1/16th inch trim. I don't want to take any chances. The old motor was a force 40 and I'm upgrading to a mercury 50. The bolt holes should be the same. I'm hoping when it sits directly on transom they will line up.

 

[smokeonthewater]

Don't hope... MEASURE and test.

Just because the old motor was down as low as possible doesn't mean it SHOULD have been...

Mercury and force aren't the same manufacturer... Merc bought force and sold em with slight changes for a short while.

Most modern outboards use the same sae bolt pattern but even if hey were the same brand the year is more important... IE my '75 merc uses a different bolt pattern from newer mercs (and other brands)

The good news is that if you tell us the years of your motors we can tell you what bolt pattern they use.

For the Force (Chrysler) Frank can tell ya just by sniffing the air lol.

 

[oldboat1]

Maybe consider an aftermarket tilt and trim unit if your new Merc doesn't have it -- some setback and some height options. Early Christmas present for yourself.

 

[Frank Acampora]

Mercury and Force were ALWAYS the same manufacturer--Brunswick--the manufacturer of Bayliner and Maxum. West Bend begot Chrysler which was forced by the feds to sell out to Brunswick which named the engines FORCE with no changes initially.HOWEVER until the mid 90s, Mercury and Force engines had different mounting designs. In the mid to late 90s, Force engines had Mercury design lower units and Mercury style mounting and tilt/trim.

as I said, you really need to test fit the engine before installing transom trim. Thicker is always better if it will fit. Secondly, there is NO difficulty in drilling four new transom holes and plugging the old ones.