I need to change the outboard motor mount on my 1976 O'day 25. Current outboard is an old Evinrude 9.9 two stroke. I would like to get a replacement motor mount that will accomodate a 9.9 four stroke when I have to updgrade. Any suggestions from fellow sailors? Also, why is is that some of the mounts say they cannot be used with four strokes? Thanks, Corey S/V Donna Lynn
Outboard Motor Bracket - O'Day 25'
- Thread starter Corey16781
- Start date
- Status
Issues
Four stroke engines not only weigh more than their hp-equivalent two stroke cousins, they also generate more torque. This means that a four stroke engine is going to be putting more strain on the mounting bracket than a two storke engine of equivalent hp. That is why many mounting brackets are not capable of handling a four stroke engine. It is easy to find mounting brackets that are rated for four stroke engines, but the chances are that it will not have the same bolt pattern or footprint as your existing mounting bracket. You will probably have to drill new holes in your transom to accomodate the mounting bolt pattern of the new bracket. You may also want to beef up the transom by epoxying a piece of marine-grade plywood to the inside of the transom where the bracket will be mounted. This will help spread the load. However, the biggest pain in this process will be if you need to replace your spacer block. This is that triangular hunk of fiberglass that is mounted on your transom in between the bracket and the transom. Its function is to allow the engine sufficient space to have the engine tiller arm extended fully, as well as keeping the engine at the proper angle to the hull. Your new four stroke rated bracket might be able to do these jobs without the spacer block, but if you still need that extra space, you will have to replace it. All of the four stroke brackets I have seen have a much wider footprint than the two stroke brackets. The Oday spacer blocks were specifically made to be just wide enough to accomodate the two stroke brackets. If your four stroke bracket is too wide, then you will have to fabricate a new spacer. I have seen various suggestions on this site about how to do that. The one that appealed to me the most was to use Star Board or similar material. No maintenance, no painting, no fuss. Good luck.
Four stroke engines not only weigh more than their hp-equivalent two stroke cousins, they also generate more torque. This means that a four stroke engine is going to be putting more strain on the mounting bracket than a two storke engine of equivalent hp. That is why many mounting brackets are not capable of handling a four stroke engine. It is easy to find mounting brackets that are rated for four stroke engines, but the chances are that it will not have the same bolt pattern or footprint as your existing mounting bracket. You will probably have to drill new holes in your transom to accomodate the mounting bolt pattern of the new bracket. You may also want to beef up the transom by epoxying a piece of marine-grade plywood to the inside of the transom where the bracket will be mounted. This will help spread the load. However, the biggest pain in this process will be if you need to replace your spacer block. This is that triangular hunk of fiberglass that is mounted on your transom in between the bracket and the transom. Its function is to allow the engine sufficient space to have the engine tiller arm extended fully, as well as keeping the engine at the proper angle to the hull. Your new four stroke rated bracket might be able to do these jobs without the spacer block, but if you still need that extra space, you will have to replace it. All of the four stroke brackets I have seen have a much wider footprint than the two stroke brackets. The Oday spacer blocks were specifically made to be just wide enough to accomodate the two stroke brackets. If your four stroke bracket is too wide, then you will have to fabricate a new spacer. I have seen various suggestions on this site about how to do that. The one that appealed to me the most was to use Star Board or similar material. No maintenance, no painting, no fuss. Good luck.
Bracket
Corey, The main reason given is torque but i have my suspicions. Go to the ODay web-site's archives. Search under Outboard Motor Bracket and 25. There you will find a whole history one this one subject. I switched my motor from a Mercury Mariner 15hp 2 stroke to a Yamaha 9.9 4 stroke two years ago without changing the bracket. But my bracket is homemade (came with boat) and has rubber supports that when lowered, rest against the stern absorbing most if any torque stresses. Fair winds Tom
Corey, The main reason given is torque but i have my suspicions. Go to the ODay web-site's archives. Search under Outboard Motor Bracket and 25. There you will find a whole history one this one subject. I switched my motor from a Mercury Mariner 15hp 2 stroke to a Yamaha 9.9 4 stroke two years ago without changing the bracket. But my bracket is homemade (came with boat) and has rubber supports that when lowered, rest against the stern absorbing most if any torque stresses. Fair winds Tom
I did it
I bought a nice expensive new bracket from West. First check carefully the movement deminsions. The one I bought says it swings through 15 inches. Now I assumed that meant the foot of the motor in the full down position is 15 inches lower than the foot in the full up position. They appear to measure that as 7.5 down and 7.5 back up. The holes lined up perfectly. I couldn't believe the luck. I mounted it only to find that the cavitation plate barely made it into the water. If I move away from the transom the prop clears leaves the water. BUT IT DOES IT WITH TORQUE! These beefy mounts are hell to lower without the engine. I mounted mine and was in the dingy pulling down on the mount handle and couldn't get it to budge. Put the motor on and down it went though with some effort. I was looking for some locking pin I had over looked. I weigh 250 so I can't figure why the engine made such a difference. Don't look for the pin. Mount the engine. I'll have to drop it but I can only go a couple of inches as the bottom holes are pretty clost the bottom of the boat. I didn't have a spacer block on the old one but will be making one as that will get you a bit more depth as it cants the engine back and down (not much). Also without the block its hard to get the handle out far enough to "unlock" the mount and move it down. Its real close to the transom. I'd shop for a bracket that will allow more downward movement. Mike
I bought a nice expensive new bracket from West. First check carefully the movement deminsions. The one I bought says it swings through 15 inches. Now I assumed that meant the foot of the motor in the full down position is 15 inches lower than the foot in the full up position. They appear to measure that as 7.5 down and 7.5 back up. The holes lined up perfectly. I couldn't believe the luck. I mounted it only to find that the cavitation plate barely made it into the water. If I move away from the transom the prop clears leaves the water. BUT IT DOES IT WITH TORQUE! These beefy mounts are hell to lower without the engine. I mounted mine and was in the dingy pulling down on the mount handle and couldn't get it to budge. Put the motor on and down it went though with some effort. I was looking for some locking pin I had over looked. I weigh 250 so I can't figure why the engine made such a difference. Don't look for the pin. Mount the engine. I'll have to drop it but I can only go a couple of inches as the bottom holes are pretty clost the bottom of the boat. I didn't have a spacer block on the old one but will be making one as that will get you a bit more depth as it cants the engine back and down (not much). Also without the block its hard to get the handle out far enough to "unlock" the mount and move it down. Its real close to the transom. I'd shop for a bracket that will allow more downward movement. Mike
Mike - which bracket did you buy?
I replaced the bracket on my 272, when I bought a Tohatsu 9.8 XL shaft 4 stroke engine, and it works okay. My problem is that the bracket springs aren't strong enough to lift the engine up and my back is starting to notice it. Getting older has some disadvantages, I'm finding, and my 240 lbs. hanging half off the transom is not a pretty sight!
I replaced the bracket on my 272, when I bought a Tohatsu 9.8 XL shaft 4 stroke engine, and it works okay. My problem is that the bracket springs aren't strong enough to lift the engine up and my back is starting to notice it. Getting older has some disadvantages, I'm finding, and my 240 lbs. hanging half off the transom is not a pretty sight!
Hey Rich ---
I solved my motor lifting problem by using a small 4-part block and tackle system. It was a vang for another boat. The line used in the block and tackle system is 3/16 line. One end attaches to the pulpit and the other to the outboard. When you are set to retrieve the moter, trip the bracket release and haul away on the block and tackle. For me it really saves the day. Have a good day!! Tom
I solved my motor lifting problem by using a small 4-part block and tackle system. It was a vang for another boat. The line used in the block and tackle system is 3/16 line. One end attaches to the pulpit and the other to the outboard. When you are set to retrieve the moter, trip the bracket release and haul away on the block and tackle. For me it really saves the day. Have a good day!! Tom
Good ideas
Teepee…thanks for that suggestion. A few folks here on Lake Norman have done this trick and it works well. I’ve hesitated to use the vang approach mainly because it sorta adds to the visual clutter already around the pulpit/transom (ladder, grill, antenna, etc.). I’ve considered going the route Charles has taken and fabricating an adapter plate to fit between the wedge and an adequate mount. I really want one that will easily pop the motor up, even if it means having to lean on it a bit when dropping it into the water.
Teepee…thanks for that suggestion. A few folks here on Lake Norman have done this trick and it works well. I’ve hesitated to use the vang approach mainly because it sorta adds to the visual clutter already around the pulpit/transom (ladder, grill, antenna, etc.). I’ve considered going the route Charles has taken and fabricating an adapter plate to fit between the wedge and an adequate mount. I really want one that will easily pop the motor up, even if it means having to lean on it a bit when dropping it into the water.
outboard bracket
I just finiswhged this project on a 222. I switched to the honda 9.9 long shaft. The bracket that I went with was the Garlick 7091 which has a 15" travel matching what was preciously on the boat. As stated previously it had a larger foot print than the old one. I made the wedge by laminating 4 pieces of Azec lumber together giving me a block 4x10x10. I then cut that in half on the diagonal.( it would have been easier with a band saw but i got it done with a regular saw. To mount it on the transom I took the old wedge and used that as a template for the first four holes (becareful that you match the angle with the holes in your transom.) I used the middle holes to secure it to the transom (dry Fit it First) then i put the bracet in place using the two holes tat were already drilled and put in two additional 5/16 bolts in place. With those bolts taking the weight I drilled two additional holes in the wedge using the bracket as a guide. Next step was to put 5200 on the back ofthe wedge and in the bolt holes to both give me some additional strenght and a good seal. I am relying mainly on the 6 5/16 bolts wich are backed up with 3/4 plywood inside and oversized fender washers. To get to these bolts I installed an inspection port in the fule locker which made it much easier to work. Be careful with the top bolts they need to be a minimum of 5" long to give you enough thread space. If anyone needs a wedge you can Have the other halv of mine if you are in Ma.
I just finiswhged this project on a 222. I switched to the honda 9.9 long shaft. The bracket that I went with was the Garlick 7091 which has a 15" travel matching what was preciously on the boat. As stated previously it had a larger foot print than the old one. I made the wedge by laminating 4 pieces of Azec lumber together giving me a block 4x10x10. I then cut that in half on the diagonal.( it would have been easier with a band saw but i got it done with a regular saw. To mount it on the transom I took the old wedge and used that as a template for the first four holes (becareful that you match the angle with the holes in your transom.) I used the middle holes to secure it to the transom (dry Fit it First) then i put the bracet in place using the two holes tat were already drilled and put in two additional 5/16 bolts in place. With those bolts taking the weight I drilled two additional holes in the wedge using the bracket as a guide. Next step was to put 5200 on the back ofthe wedge and in the bolt holes to both give me some additional strenght and a good seal. I am relying mainly on the 6 5/16 bolts wich are backed up with 3/4 plywood inside and oversized fender washers. To get to these bolts I installed an inspection port in the fule locker which made it much easier to work. Be careful with the top bolts they need to be a minimum of 5" long to give you enough thread space. If anyone needs a wedge you can Have the other halv of mine if you are in Ma.
- Status