Outboard motor mount on Oday 28...advise requested

[flyhop]

Oday 28 was bought with saildrive removed and outboard mounted on a Garelick motor mount (older model# 71090). Outboard and mount were used when applied to boat by PO. Locking pin of mount broke, springs were shot, and "fix" is denied by Garelick (too expensive...may as well get a new one). Bottom line is that I have to get a new one.The Oday 28 is a 7300 lb boat. Boat is being kept on a freshwater lake in N Alabama (Guntersville), and we don't plan to take her out on the coast. A 10 hp outboard can get her close to hull speed (over 6.5 knots) but I worry that this large of a boat will put an undo amount of torque and stress on a motor mount. Garelick is less than enthusiastic about their motor mount being the sole source of auxilliary power on this boat, but putting in a new inboard gas/diesel is out of the question. The only motor mount they will recommend is their Hydro-assisted motor mount. I may not have spelled it correctly, but it retails for over $1,800. Here's my question. Am I worrying unnecessarily (read: am I being a sissy) that the 71090 is too lame a motor mount to push this size of a boat? In this lake, it's used primarily to get us out of the slip and out into the main channel of the river (Lake Guntersville is really a widening of the Tennessee River created by Guntersville Dam) and for us to bang around the lake when the wind dies.Second but related question....how many of you have a large boat being pushed by a smallish outboard motor on a retractable motor mount? As always, thanks in advance.

 

[Benny]

My 2 cents.

It would seem to me that rather than the weight of the boat it is the weight and thrust of the engine which comes to bear on the motor mount. The wetted surface of the hull because of friction exerts a force opposing the engine thrust but this force is much lesser than the weight or displacement of the boat. Get a motor mount rated for the weight and horse power of the engine. I would be more concerned with reinforcing the transom to avoid flex by using a backing plate to distribute the forces through a larger area. My other area of concern would be motoring in the ocean as the forces imparted by large waves could quickly exceed the design limits of an outboard mount but in a lake with protected waters you need not worry about this. My experience has been that these mounts are stronger than they look. I have been on a small boat at sea in instances where I thought the engine was going to get ripped out of the transom as it was swinging 30 degrees from vertical from side to side with the powerhead getting submerged briefly a couple of times and it made it through and never even quit. Hope this info helps.

 

[Tom Monroe]

Benny's right, and a couple other points

I sail a C27, about the same size/weight of your boat ...The motor mount that originally came on the boat was spec'd for the older two stroke OB's ... much lighter and less torque. Whe I got a new Honda 4-stroke, I installed a new motor mount, sized for the Honda's weight and torque. It works fine, ven when the boat is wallowing around in quartering seas. Like Benny says, it's the weight and torque of the OB that drives your decision, not the weight of the boat.A couple other points ...A 9.9 hp Honda OB drives my boat quit nicely.An extra long shaft is a great feature since it helps keep the motor from cavitating when the boat is hobby horsing in bigger chop.If it's a conversion, be sure the mount has enough backing and load distribution. If the transom was not originally designed (thick enough layup) for a motor mount, the load may need to be distributed over a wider area.One thing I do to make living with an OB and motor mount easier ... I hooked a small boat vang between the OB lifting handle and the top bar on my pushpit. Makes lifting the whole thing really easy and safe.Tom MonroeCarlyle Lake

 

[flyhop]

Other comments??

nm