Force Transom Mount problems...

cordell

Petty Officer 1st Class
Joined
Mar 28, 2008
Messages
308
My new to me Bayliner Capri 1990 in year and 18' in length has holes for the motor that used to be on the boat. I want to add my 1987 85 hp Force motor to it, this is were the problem comes. The pic shows my hole pattern that is OK to a point. The top 2 holes need to be sealed up. The bottom 2 work for my motor. The down view of my transom has a measurement of 3 inches. Well you see my motor has the 2 screw type fasteners for the top and that measures 2.5 inches. I need 1/2 inch somewhere! I was thinking take the screw type fasteners out and running lag bolts into my transom???? Is this the correct fix, or the oak ball way? If it is the oak ball way what do I need to do that doesn't involve me buying a different motor OR motor mount for my motor...The top 2 hole do not line up with the screw type fasteners either so adding some heli coil will not work, unless I fill them and drilled new ones? HELP lol

thanks
cordell

holes
100_0450-1.jpg


top view of transom 3 inches thick
100_0451-1.jpg


transom mount on my 1987 85 hp force 2 3/4 opening
100_0452-1.jpg
 

maxum247

Lieutenant
Joined
Sep 18, 2007
Messages
1,363
Re: Force Transom Mount problems...

Are you saying the big washers that are on your engine lack a 1/2" going down on the stern far enough so the washers get a good bite on the transom?

As far as filling the holes some epoxy with filler mixed in to the consistancy of pudding and a couple of wooden dowels cut to set just inside the transom surface about an 1/8" inside and out so that you have room to fill over the dowel ends will make it water proof and do the job!
 

cordell

Petty Officer 1st Class
Joined
Mar 28, 2008
Messages
308
Re: Force Transom Mount problems...

No the opening of my transom mount with washers is 2 1/2 inches. If I were to remove those screw clamps I would have a opening of 2 3/4 inches. My transom is almost 3 inches thick...not a depth issue, the opening is not big enough to slide over or onto the transom...

cordell
 

maxum247

Lieutenant
Joined
Sep 18, 2007
Messages
1,363
Re: Force Transom Mount problems...

Sorry Cor I missed the fine print the first go round!
 

cordell

Petty Officer 1st Class
Joined
Mar 28, 2008
Messages
308
Re: Force Transom Mount problems...

What I was thinking after I fill the top holes I could remove the screw clamps from the transom mount. Then take a grinder and grind the inside edge where the clamp "used" to be, if you look it seems as if there is a little nub there. But by doing this I think I could get the correct width of 2 7/8 and then be able to lower my motor onto my transom. I would then predrill 3/16 holes were the screw clamps were and run lag bolts into the transom...what do you think? Maybe if I drilled over sized holes and filled the holes with epoxy and drill/lag into that, OR drill over sized holes and set a threaded sleeve of some sort in there with epoxy and then I could use a stainless steel bolt to clamp the motor down at the top...Is the top bolts/clamps that important as long as I have the bottom bolts in???

cordell
 

maxum247

Lieutenant
Joined
Sep 18, 2007
Messages
1,363
Re: Force Transom Mount problems...

No the opening of my transom mount with washers is 2 1/2 inches. If I were to remove those screw clamps I would have a opening of 2 3/4 inches. My transom is almost 3 inches thick...not a depth issue, the opening is not big enough to slide over or onto the transom...

cordell
If you remove the washers as though you were going to thru bolt at the top of the mounting bracket and line up the bottom two holes that match how much of a gap do end up with between the top of the transom and the underside of the mounting bracket?
 

cordell

Petty Officer 1st Class
Joined
Mar 28, 2008
Messages
308
Re: Force Transom Mount problems...

If I remove the washers clamps and I set the motor on (after a little grinding) the underside of the mount will sit on top of the transom. The lower holes are a perfect match for the mount. The only spot I will be grinding a bit is right above the clamp washer, seems to nub out right there. if that was done a perfect fit...just no top bolts.:(

cordell
 

maxum247

Lieutenant
Joined
Sep 18, 2007
Messages
1,363
Re: Force Transom Mount problems...

What I was thinking after I fill the top holes I could remove the screw clamps from the transom mount. Then take a grinder and grind the inside edge where the clamp "used" to be, if you look it seems as if there is a little nub there. But by doing this I think I could get the correct width of 2 7/8 and then be able to lower my motor onto my transom. I would then predrill 3/16 holes were the screw clamps were and run lag bolts into the transom...what do you think? Maybe if I drilled over sized holes and filled the holes with epoxy and drill/lag into that, OR drill over sized holes and set a threaded sleeve of some sort in there with epoxy and then I could use a stainless steel bolt to clamp the motor down at the top...Is the top bolts/clamps that important as long as I have the bottom bolts in???

cordell

Your defenately going to want to get the clamp brackets as far down on the transom as you can, the futher the better. The clamps or bolts in this case are there to keep the engine from twisting on the transom sideways and jumping off the stern.
Remember the prop is always trying to push itself under the boat, get those brackets down on the transom good as you can, the futher the better.
The more bolt size wise you can get in there without weaking the metal of the mounting bracket the better, be careful with the grinding not crazy about that!

Remember to keep the anti ventalation plate even with the bottom of the boat or there abouts.

Ok I missed something with the 3/16 holes I'm thinking your going to lag into the stern through the original top mounting holes after removing the washers.
 

cordell

Petty Officer 1st Class
Joined
Mar 28, 2008
Messages
308
Re: Force Transom Mount problems...

I found this doing some research here in iboats forums. my only concern is this stay true to when mercury took force over? Or did they only change the electrical systems?

all transom brackets and Trim/Tilt are interchangeable between all 3cyl and larger Chrysler, Force, and USMarine engines. This is because the swivel bracket is the same for all engines. .

cordell
 

maxum247

Lieutenant
Joined
Sep 18, 2007
Messages
1,363
Re: Force Transom Mount problems...

If I remove the washers clamps and I set the motor on (after a little grinding) the underside of the mount will sit on top of the transom. The lower holes are a perfect match for the mount. The only spot I will be grinding a bit is right above the clamp washer, seems to nub out right there. if that was done a perfect fit...just no top bolts.:(

cordell

No top bolts, don't like that, the bottom bolts will snap for sure without the top bolts in there's a lot of torque on that lower end!
 

maxum247

Lieutenant
Joined
Sep 18, 2007
Messages
1,363
Re: Force Transom Mount problems...

I found this doing some research here in iboats forums. my only concern is this stay true to when mercury took force over? Or did they only change the electrical systems?



cordell

If there the same and you can find a good used bracket that would be the way to go I think!
 

Mark42

Fleet Admiral
Joined
Oct 8, 2003
Messages
9,334
Re: Force Transom Mount problems...

I would go ahead and grind off the nub to get the motor mounted. Remove the screw clamp bolts leaving an open hole and mount motor. Attach the lower bolts to secure the motor well. Then get a length of 3/16" x 2" metal bar and cut to a lenght long enough to cover both of the top threaded clamp holes, and bend the bar in a Z shape at each end so it touches the transom.

Drill holes in the bar and use bolts to mount the bar to the old clamp threaded holes, and drill holes in the Z bent ends to use bolts through the transom. You may have to heat the bar to bend it. Basically, you are just moving the transom bolt holes a little to the outside of the motor mounting bracket. The new metal bar will bolt securely to the old clamp holes, and to the transom. Be sure to paint the new metal bar well to prevent rust.

Mark.
 

cordell

Petty Officer 1st Class
Joined
Mar 28, 2008
Messages
308
Re: Force Transom Mount problems...

Ok here is what I came up with as the bending will be hard to get it just right. I will take a 3/16 steel plate about 2 1/2 inch thick. Then drill holes to line up with transom mount, another set of holes to bolt through the transom. These bolts will have a steel sleeve and washers at both sides of transom. I think this will work. A little okie rigged but will work. Anybody have thoughts? Good and the bad I dont care. lol

cordell

11111.jpg
 

cordell

Petty Officer 1st Class
Joined
Mar 28, 2008
Messages
308
Re: Force Transom Mount problems...

I just thought up another way to do this. Inset washers flush with the transom. I lower the motor on and then use the original screw clamp bolts to tighten to the inset washers. Please forgive my horrible paint drawings. lol:redface:

cordell

11111234r77e.jpg
 

Mark42

Fleet Admiral
Joined
Oct 8, 2003
Messages
9,334
Re: Force Transom Mount problems...

Yep, thats the idea. And I think your right about not needing to bend the bar, its only offset about an inch or so from the transom. Washers or spacer cut from pipe should work. I would try to keep the transom through bolts as close as possable to the motor mounting bracket (leave space for large washers). Don't forget to use a good sealer. I like Boatlife Boatseal. But 3M makes some good sealers too.

The nice part about this mod is that the motor has no permanent damage, and the transom holes can be filled with epoxy with no bad effects, should it not perform as as we hope.

I don't see any reason why this will not work for you. Post some pics when your done.
 

Mark42

Fleet Admiral
Joined
Oct 8, 2003
Messages
9,334
Re: Force Transom Mount problems...

I just thought up another way to do this. Inset washers flush with the transom. I lower the motor on and then use the original screw clamp bolts to tighten to the inset washers. Please forgive my horrible paint drawings. lol:redface:

cordell

11111234r77e.jpg

That should work too, but you need "washers" without holes to tighten the bolts to, right?
 

cordell

Petty Officer 1st Class
Joined
Mar 28, 2008
Messages
308
Re: Force Transom Mount problems...

Yep, thats the idea. And I think your right about not needing to bend the bar, its only offset about an inch or so from the transom.


That and the transom mount is going to be a tight fit! It will take me more time trying to get that thing on all the way than to fab the steel strap!

cordell

Correct washers with NO holes is what I was thinking. I have been pondering this all day at work. lol
 

Frank Acampora

Supreme Mariner
Joined
Jan 19, 2007
Messages
12,004
Re: Force Transom Mount problems...

Well Cordell, you are Sh-- out of luck--up the creekballs to the wall--etc. No matter what you do to the transom and the engine clamps, you are going to weaken the system. You CAN buy the newer thru-bolt clamps but my experience has been that swapping out the tilt/trim is very aggravating. The bars tend to corrode into the clamps very well.

If it were my boat, I would go to my local fabricator or welding supply and buy two pieces of heavy duty aluminum extruded 6 inch channel --about 15 inches long. at least 3/16 web and at least 5/16 flanges. Bolt them to the transom far enough apart to fit the engine clamps and either get a 1/2 inch aluminum plate or a good solid piece of hardwood at least 1 inch thick backed with 1/8 aluminum both sides to carry the engine. Use 1/2 inch stainless bolts. In other words, make yourself a jackplate. Seal the existing holes in the transom. It will be far easier to fabricate and mount, it will allow you to tailor the engine height, and it will set the engine back into cleaner water. Won't be cheap--but it will be cheaper than a commercial jackplate and it probably will be the fastest and most secure fix.

However, before you do this, check that there is enough slack in the steering cable to allow the set-back.
 

cordell

Petty Officer 1st Class
Joined
Mar 28, 2008
Messages
308
Re: Force Transom Mount problems...

get a 1/2 inch aluminum plate or a good solid piece of hardwood at least 1 inch thick backed with 1/8 aluminum both sides to carry the engine.
.

I have a 1/2 inch aluminum plate that came off my old glastron I had this motor on. This idea almost sounds easier but I don't think I have enough room with my steering cable to go back the 6 plus inches.:mad: That cable is drawn pretty tight the way it sits, is there a way to extend without hitting the wallet to bad??

cordell
 
Top