Checking torque on motor mounting bolts?

[Rae]

I was checking things over on my motor the other day and I decided to check the torque on the motor mount. I was surprised to find that I needed to turn almost a complete turn to achieve 55lb/ft of torque.

Now I'm concerned that I have broken the silicone seal in the bolt holes, I tried to turn the nut itself and not the bolt but I can't be sure I didn't. I haven't put the boat in the water yet so I don't know if it leaks or if I would even see it leak if it did. Should I take the bolts out one at a time and re-seal and re-torque or am I beind paranoid?

Rae

[4JawChuck]

Reseal them, very cheap insurance.

[hommer23]

x2 reseal and you can put a nylock nut or star washer on them to prevent them from backing off again. May just leak on the transom board and rot it out before you see it.

[staylor]

..it's also a good idea to check the torque on the tilt tube. I found that whenever I had to put a 1/2 turn or more into the mount bolts, that the tilt tube was also a bit loose- this was true on both Mercs and Evinrudes.
Doug

[REW]

Rae,
One post made the suggestion that you needed to put a lock on the bolts to keep it from getting loose.
I doubt very much that the bolt has gotten loose.

Rather, I am guessing that your transom is compressing a bit due to age and potential rot.

I would suggest that you remove your bolts, one at a time. When you do remove each bolt, use a sharp hook bent at right angles to probe in the hole in the transom left by the removed bolt. Use the hook to check the integrity of the transom. It is quite possible that you are beginning to get some rot going on in the transom. It is pretty common for all boats that have wood in their transom to have this to some degree. All that a person can do, is to seal the holes in the best way possible and keep an eye on the transom for any signs of rot or weakness.

In any event, when you remove each bolt - one at a time, use a new stainless bolt with a locking insert on the bolt. Also, be sure to use as large and as thick a washer as possible when replacing the nut and bolt after sealing the hole very well. The larger thicker washer will help to spread the motor load over a larger part of the transom.

A good idea that is used by many folks when they mount a motor is to use a piece of angled aluminum that spans as large a section of the transom as possible to again, spread the motor loads over a larger part of the transom. This spreading of the pressure helps to reduce the pressure on the transom that is right around the motor mounting bolts. They just take a piece of 1/4 inch thick angled aluminum, cut it to a length that can be fit on the face of the transom - if there is room in the motor mounting area. If necessary, longer transom mounting bolts are used to accommodate the extra thickness of the aluminum braces on the transom.

It is also a good idea to NOT use silicone in the transom for sealing the bolt holes. Silicone is not resistant to gasoline that might be in the area from motor related issues. Rather, it is better to use one of the 3M marine sealants that are gasoline resistant.

Good luck
REW