3.0l TKS Front Engine Mount

[Matt Shackleton]

So the Bertram 20 re-glass is finished. 3.0l TKS motor is back in but ....front mount cross member is too high to align motor to transom/gimbal bearing properly. Thinking of engineering a new front engine mount - anyone seen this done before or am I kidding myself?

[ktm_2000]

ahh..... the pain. I finally had enough of my IOs and went down the outboard path after having a coupler go bad for the second time.

This is the area if you mess it up, you will revisit it. so build it and build it well.

What does the engine bay of the 20' look like? can you share a pic?

I have the 2 old aluminum brackets which my 3.0 L motors where attached to. See the area near the SS washer
https://photos.app.goo.gl/Y11f5HTPnnXwi4HMA

In my case the area which the aluminum was bolted to had a wood core that was rotted on the port side. The rotted wood allowed the fiberglass to flex on the back side and ever so slightly putting the engine out of alignment when the engine torque was put to it. Nothing was noticeable at rest.

The brackets are made out of aluminum and are made to be set flat against a vertical bulkhead. If you are interested, I could ship them to you for a donation of the shipping costs to this site in my name.

[Matt Shackleton]

Hey KTM, thanks for the reply. Yep, I somehow feel like this is going to be a bugger in the long run, but as you say, doing it right might delay that. I'd love to upload some photos but can't figure out how to do it...?
The engine bay doesn't allow for the setup you used - I have to replace the triangle bracket that the motor sits on - the bracket that the alignment adjustment bolt goes through - with an engineered one. So not the bracket that goes across the front of the motor, but the bracket that that bracket sits on - referred to in the manuals as the front engine mount. The only alternative is to have the cross member rebuilt which means opening up the glass work again. Ah!

[Matt Shackleton]

[Matt Shackleton]

[Matt Shackleton]

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[Matt Shackleton]

[Matt Shackleton]

[Matt Shackleton]

[John Swick]

Nice job on the refinishing.
Redo the cross member or design a new motor mount?
Some see six, some see half a dozen.
I'd probably redo the cross member, but that's just me.
How far is it out?

[Matt Shackleton]

70mm/2.75” it’s out by John. I’m going to see if the re engineered mount works first and if no joy will redo the X member. Hopefully this weekend.

[ktm_2000]

The challenge as I see it is to figure out what you need to support that front motor mount and how high off the bottom of the hull it needs to be.

One way I've seen this done is to have the 2 bolts in the back engine mounts loosely and put the front of the engine on a hoist with the front motor mount installed and set so there is travel up and down within its adjustment range and use the drive alignment tool to figure out the proper height for the front of the motor engine. Once you determine the proper height and make a support you will have fine tuning adjustment capability on the motor mount.

as shown in the pics, is the engine at the right height? seems a little bit low to me

If it is in the right position you only need a small triangular shaped pad glassed into the boat. The height of it It would probably be less than the area under the current cross brace

I hope in this mix you have a drive alignment tool, to properly set these you need one, it needs to slide in through the gimbal bearing into the coupler with finger pressure and you need to rotate the motor and test that it is the same ever 90 degrees

[Matt Shackleton]

Thanks KTM, and yes the motor is sitting low but this is because I've got it resting on the cross member. The bracket we are engineering will sit on the cross member - the trick is to get its height right to allow for up and down travel of the front of the motor. I'll post a pic when we try it out. Yep to the alignment tool - in fact that's the bit where the mechanic comes into to make sure its all tickety boo. Those tools are over A$270!!!

[ktm_2000]

Matt,

I googled the alignment tool and one came up on ebay for $20, much less expensive than the $100 + one I bought years ago. To allow your project to move forward faster you might want to pick one up, get the engine
mount base close to right then after the engine is installed bring the boat to your mechanic to fine tune everything to make sure it is absolutely right.

From your other post it looks like you really know your way around fiberglass work so a motor mount base should be fairly easy for you to fabricate.

[Matt Shackleton]

Good idea KTM. The issue with cost for me in Oz is that the tool is US$20 but the shipping is US$190!! BUT I have a solution with a mate travelling from Canada in a couple of weeks. You're right though - get it all sorted and aget a mech to fine tune - won't run it with leg until then. And cant take credit for the glass work - that is all done by a good guy who is now .... retired!

[Matt Shackleton]

Engine is yet to be fine-tune aligned, but the front engine mount is complete and engine resting in place nicely.




The galvanised bolts either side of the adjustment screw are to add additional strength to the C iron.

[ktm_2000]

looks good, welding is much faster than glass work.

one question why not have the 2 front bolts fully surrounded by steel?

[Matt Shackleton]

Good question. Getting the bolts in and out is a pretty fine thing as it is and I need to be able to tighten them into place once the engine adjustment screw has been set. But it would add some serious strength to it I agree.