Portsmouth NH has some of the fastest tide current in the world. I have to plan when to enter the harbor because the speed can exceed the hull speed of my O'Day 25. Has anyone here put a 15 hp motor on their '25? What would you recomend for a back up? I speculat more than 8 hp. is a waste of money. Also more than 8 hp might over stress the transom. Thoughts?
OB motor size? brand?
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15 not too big
The Oday 23 brochure says that you can put up to a 15 hp engine on; it stands to reason that the transom of the 25 could take that big an engine as well. The strength of the bracket you have is really the limiting factor. What do you mean by a "back up"? Do you mean a back up to the 15 hp engine (a second outboard mounted alongside the 15), or a back up choice if the 15 is too big? I used to have a 9.9 mounted on my Oday 23. I repowered to an 8 (both two stroke), and have never missed the lost hp.
The Oday 23 brochure says that you can put up to a 15 hp engine on; it stands to reason that the transom of the 25 could take that big an engine as well. The strength of the bracket you have is really the limiting factor. What do you mean by a "back up"? Do you mean a back up to the 15 hp engine (a second outboard mounted alongside the 15), or a back up choice if the 15 is too big? I used to have a 9.9 mounted on my Oday 23. I repowered to an 8 (both two stroke), and have never missed the lost hp.
15HP motor
I have a l975 O'day 25 and two years ago I replaced a 9.9 Johnson with a 15HP 4 stroke Yamaha. I reworked the transom with backing plates inside the Transom as well as outside and replaced the motor bracket with a heavy duty one thats rated for 169Lbs. and 30 HP. My wife and I love the setup as it is strong and the motor runs very well also. I guess at about have throttle we go about 5 knots.
I have a l975 O'day 25 and two years ago I replaced a 9.9 Johnson with a 15HP 4 stroke Yamaha. I reworked the transom with backing plates inside the Transom as well as outside and replaced the motor bracket with a heavy duty one thats rated for 169Lbs. and 30 HP. My wife and I love the setup as it is strong and the motor runs very well also. I guess at about have throttle we go about 5 knots.
outboard
I had a Yamaha 9.9 hp e;lectric start 4 stroke on my old O'Day 240 and had power to spare. I think 15 hp would be over kill based on your hull speed and displacement. I did have an extra plate welded on the bracket as it flexed under full throttle.
I had a Yamaha 9.9 hp e;lectric start 4 stroke on my old O'Day 240 and had power to spare. I think 15 hp would be over kill based on your hull speed and displacement. I did have an extra plate welded on the bracket as it flexed under full throttle.
Price will tell
Thank you all for replying. The tide speed will hit 6 knots at the tight places in the channel. I have some 1/4 inch aluminum plate and I can re-enforce the transom if I have to. My boat has turned from a minor repair job to a 2 year ordeal. I think I will get a motor with electric start and a charging system. It will be expensive but there are two draw bridges that I have to go under that have a reputation for eating sailboats every year. The charging systems and electric start are rare on the smaller motors but the price starts getting tall on the larger motors with accessories. I was just curious if anyone had damaged their boat with the weight and power of a 15 hp motor. My old inboard Vire 7 will run but if it ever fails when I need it, the briges would eat my mast. That would be Really Bad! Thanks again.
Thank you all for replying. The tide speed will hit 6 knots at the tight places in the channel. I have some 1/4 inch aluminum plate and I can re-enforce the transom if I have to. My boat has turned from a minor repair job to a 2 year ordeal. I think I will get a motor with electric start and a charging system. It will be expensive but there are two draw bridges that I have to go under that have a reputation for eating sailboats every year. The charging systems and electric start are rare on the smaller motors but the price starts getting tall on the larger motors with accessories. I was just curious if anyone had damaged their boat with the weight and power of a 15 hp motor. My old inboard Vire 7 will run but if it ever fails when I need it, the briges would eat my mast. That would be Really Bad! Thanks again.
I have a 15 HP on my O'Day 22..
My '76 22' came with a brand new Mercury 15HP. The boat and the bracket both claim to accept 15. So far i have seen no sign of stress anywhere.
My '76 22' came with a brand new Mercury 15HP. The boat and the bracket both claim to accept 15. So far i have seen no sign of stress anywhere.
can it plane?
Unless the boat can plan, you are not likely to exceed hull speed by much. So if the current is running at 8 knots & hull speed limits you to 6 you'll be going backwards slowly. No matter what, you might have to wait for the tide to slack off. On the other hand, if you are running with the tide maybe you could make 12 or 14 knots over the bottom. Not bad for a sailboat. I have little experience w/ strong tides, so I may be off base.
Unless the boat can plan, you are not likely to exceed hull speed by much. So if the current is running at 8 knots & hull speed limits you to 6 you'll be going backwards slowly. No matter what, you might have to wait for the tide to slack off. On the other hand, if you are running with the tide maybe you could make 12 or 14 knots over the bottom. Not bad for a sailboat. I have little experience w/ strong tides, so I may be off base.
'76 O25 w/ 15HP
I am a new owner of a 1976 O'Day 25, which came with a 15HP Evinrude outboard. The outboard is a 1979, and, amazingly, it has been with the boat since that year. The transom is in great shape, with no signs of undue stress. The motor, although old, will push the boat just past the 6-knot mark in slightly choppy water. One consideration; todays outboards are rated for horsepower at the shaft. My old outboard was rated for horsepower at the crank, which means the newer 15HP motors will be significantly more powerful than what I have.
I am a new owner of a 1976 O'Day 25, which came with a 15HP Evinrude outboard. The outboard is a 1979, and, amazingly, it has been with the boat since that year. The transom is in great shape, with no signs of undue stress. The motor, although old, will push the boat just past the 6-knot mark in slightly choppy water. One consideration; todays outboards are rated for horsepower at the shaft. My old outboard was rated for horsepower at the crank, which means the newer 15HP motors will be significantly more powerful than what I have.
9.9 Johnson on OD 26
I have an OD 26 (very similar to the 25) with a 9.9 Johnson sailmaaster (long shaft). It pushes the boat to about 6.5-6.8 knots in light chop. One thing, it is tough to raise the spring loaded motor bracket to full up position, so a bigger heavier motor would compound this problem.
I have an OD 26 (very similar to the 25) with a 9.9 Johnson sailmaaster (long shaft). It pushes the boat to about 6.5-6.8 knots in light chop. One thing, it is tough to raise the spring loaded motor bracket to full up position, so a bigger heavier motor would compound this problem.
anchor at the ready
If I had to deal w/ the tides & bridges I think I would keep the anchor on deck, cleated off & ready to deploy in an instant.
If I had to deal w/ the tides & bridges I think I would keep the anchor on deck, cleated off & ready to deploy in an instant.
Good point Ed!
Thank you all for your advice. I'm looking around for a motor, electric start, with a chargeing system. I think the modern 9.9 is probably the same power as the old 15 hp. model, almost, and is probably all I'll need. I'll keep the anchor ready! I lust after a new Tohatsu 9.0 but my budget says mid 80's Eevenrude/Johnson. Perhaps a loan at the bank?
Thank you all for your advice. I'm looking around for a motor, electric start, with a chargeing system. I think the modern 9.9 is probably the same power as the old 15 hp. model, almost, and is probably all I'll need. I'll keep the anchor ready! I lust after a new Tohatsu 9.0 but my budget says mid 80's Eevenrude/Johnson. Perhaps a loan at the bank?
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