motor mounts bad

[gurglegurle]

Hi guys. I've been trying to figure out a fix and need your assistance.
I've had no luck with the seach function.

I have a 20' 1991 Ski Brendella in-board direct drive PCM 351 motor.
The engine is creeping up and toward the bow. The lag screws holding the motor mounts to the stringer are coming loose. The screws will not grab the wood anymore because the hole in wood is already loose-threaded or morelikely the stringer in the particular location is rotting.

My question is how to I go about a proper repair job to firmly connect the motor to the stringer so I can ski this summer?

I've had to redrill other locations for my pylon because of similar issue.

My best plan so far is to use angle iron to sandwinch between mounts and stringer using new hardware and drill new holes.

I'll try to take some pics. Thanks for any insight and help in advance.

 

[bomar76]

Re: motor mounts bad

1. Remove engine
3. Remove tranny
3. Remove and replace rotted stringers
4. While you are at it, remove and replace all the rotted wood at pylon location.
5. Reglass areas as required
6. Replace tranny
7. Replace engine

 

[tashasdaddy]

Re: motor mounts bad

http://70silverline.250free.com/Skankybeast.html

 

[Robj]

Re: motor mounts bad

1. Remove engine
3. Remove tranny
3. Remove and replace rotted stringers
4. While you are at it, remove and replace all the rotted wood at pylon location.
5. Reglass areas as required
6. Replace tranny
7. Replace engine

As above. Yes it is alot of work, but it is the correct way to fix it.

Have a great day,

Rob.

 

[JMRuth72]

Re: motor mounts bad

What color is the wood where the lag screws are supposed to go? If it is black then it is rotted and must be replaced for strength and safety. The repair that you mentioned is not really a repair as much as it is a patch, but it won't replace the strength of the stringer that is rotting. It just transfers the load of the engine to another location on the stringer, but it won't do anything from the load of the boat itself. After you have replaced the stringers and glassed them in if you want to mount angle iron and mount the engine to that I don't see why it wouldn't work just fine to spread the load over a larger area and prevent the lag screws from stripping out again. However I think that if I was to do that I would figure out where I was going to mount the angle iron and pre-drill all the holes then disassemble everything and use a thinned epoxy in the holes and quickly reassemble everything. It would help seal the holes where the screws enter from moisture entering and rotting it out again. It is much better and safer, but not probably not easier to do the job right the first time and not have to worry about it again than to patch it and hope it holds. Good luck on your adventure.

 

[Bondo]

Re: motor mounts bad

1. Remove engine
3. Remove tranny
3. Remove and replace rotted stringers
4. While you are at it, remove and replace all the rotted wood at pylon location.
5. Reglass areas as required
6. Replace tranny
7. Replace engine

Ayuh,......

That's how it's done,...... Properly.........

Danm,....... 4 responses,... All at 5:38........

 

[gurglegurle]

Re: motor mounts bad

Wow. You guys are fast and straight...thanks for the help/replies.
My solution was definitely a patch job.

Hypothetical question:

Does the stringer have to be replaced as a whole piece?
Or can I replace only the portion(s) that is rotted?
If yes, how do I connect the pieces?

I ask because the striger is not straight. The 2 narrow and widen along the length of the boat. It is about 18" at stern, about 24" at motor area and return to about 18" toward pylon area. Could there be multiple pieces glassed together?

 

[tashasdaddy]

Re: motor mounts bad

you would have to lap the splice on each side, of stringer, and 2 ft each way from the splice. in other words a 4 ft sister splice on each side.

 

[Coors]

Re: motor mounts bad

And the lag doesn't attach to the angle iron, only to the wood in the stringer/mount.
The angle iron gives no attachment, it only gives rust stains.

 

[Bondo]

Re: motor mounts bad

The 2 narrow and widen along the length of the boat. It is about 18" at stern, about 24" at motor area and return to about 18" toward pylon area. Could there be multiple pieces glassed together?

Ayuh,...... I'm pretty sure that "Sections" can be cut out,+ replaced.........

My Old Town is built with a unitized stringer system like that,.....
All done with 3/4" plywood,+ fiberglass.....

The 1st thing you've got to do is,.......
Grab an Icepick,+ go pound some Wood,..... Or atleast try to find some that isn't Rotten....
When you know what's Good,+ what's Rotten,....
Then you can devolop a Plan.......


Btw,..... Welcome Aboard...........

 

[oops!]

Re: motor mounts bad

i just saw this thread ....and the speed of the answers.....

1. Remove engine
3. Remove tranny
3. Remove and replace rotted stringers
4. While you are at it, remove and replace all the rotted wood at pylon location.
5. Reglass areas as required
6. Replace tranny
7. Replace engine

could you be a little more specific?..........( lol )

sorry gurgle.... that was an inside (i boats ) joke......
if you need more help...were here