Engine Coupler Gone Bad...

[opti99]

Hey guys, after thinking it was my prop that was causing cavitation as I increased power I think it may now be the engine coupler that has gone bad. The problem acts like a slipping clutch in a car and has gotten progressivley worse to the point where the boat will not even plane with 2 people. Looks like the engine is going to have to come out. It's a Merc 5.7L in a Sweet 16. Question is, how the heck do you get that thing out of there?? Something I saw a while back said to rotate the engine 90 degrees and it would come out, but do the manifolds have to come off beforehand?? Any input would be greatly appreciated. Thanks.

[MOP]

Remove the drive! Carefully disconnect everything, look for ground wires near the bell housing, remove the exhaust manifolds, undo the mounts at the bases. Move forward and rotate 90 Degrees and lift it out! The rest you can figure out if handy if not just ask! The reason for removing the mounts at the bases is it gives you more clearance and lessens the chances of damage to the mounts or the threads, it is also a lot easier going back in. A little early on prep tape rags over the engine bays edges so you don't take chunks out of the gel!!!!

[BlownCrewCab]

Could it be a Prop hub that spun and not the coupler? Did you smell smoke or hear squealing?

[Pismo]

Make 100% sure it is the engine coupler before you bother pulling the engine. Put it in gear and try to turn the prop by hand. It clicks one way, try it the other and see if it slips. It should not, it should try and turn the engine over. It will overheat once totally gone.

[opti99]

I haven't smelled any smoke, but I have read what others say are symptoms of a bad coupler and I have the prop off and it looks okay. Is it possible to just slap on a mirage 23p from a bravo drive and see if it works? Would a prop hub get worse over time? I definitely agree pulling the engine is the last resort....

[opti99]

I currently have the drive off...is there anyway to test the coupler or can you only try to visually inspect it?

[mrfixxall]

put the drive back on and put the 23 prop on it and if its harder to get the boat on plane then the coupler is ok..like stated you usually get a rubber smell if the coupler is going..

[MOP]

I thought you had ascertained it was the prop, by all means either try another prop or go to your local prop shop and have them torque check yours. I have mine checked each spring at my buddies, he runs it up to 600lbs so far no signs of letting go.

[smokediver]

the manifolds do have to come off and the engine needs to turn 90 degrees to starboard ... dont know why but trust me , it goes in and out pointing to starboard ... it is also real helpful to have a few come alongs to rotate,twist , and the usual contortions involved ....

[Pismo]

I hope you do not need to change the coupler as the jury is still out as to exactly what is wrong but if you do I was able to change a coupler once by lifting the engine a very small bit and then turning it about a 1/8th turn in the engine bay without having to completely remove it from the engine bay. Saved much time and effort.