alpha 1 drive problem

Hi, new here to the boat repair scene. I have a 88 merc 4.3 alpha 1 setup with some issues. I was cruising at about 3000 rpm last night when the boat started to vibrate suddenly and slow down at the same time. I put it neutral, then back into gear same problem. Next I turned the engine off and tilted the drive up to check the prop, but it looked ok. I then tried to start the engine but it made whinning noises and wouldn't turn the engine over. To make a long story short, got her home pulled the starter and I can spin the flexplate thing by hand. Never worked on a boat before but I know you shouldn't be able to spin by hand like some bolts broke or came loose. If someone could give me some help on how this drive coupler setup works that would be great!

Re: alpha 1 drive problem

The coupler is bolted to the crankshaft end on that model. IF you can turn what you are calling a flex plate, thru the starter hole, that's the flywheel, and something is big time broken.
Time to pull the engine and see what happened.

Re: alpha 1 drive problem

Yes I can turn the flywheel by hand through the starter hole. I was kind of thinking I was going to have to pull the engine, damn! Is it a total pain or can an average mechanical guy do it? I have pulled engines in cars before but this is a little different. Can you pull and engine from a boat with a cherry picker like you would in a car or no? Thanks for the help guys.

Re: alpha 1 drive problem

It actually is not as difficult to pull an engine as you might expect. I was able to swap a 4.3L into a 3.0L boat using a standard cherry picker (thats 2 removals and 1 installation). The bottom of the engine just cleared the transom with the cherry picker.. probably had 6-8" to spare.

Re: alpha 1 drive problem

Ok so I need to pull then engine and fix whatever broke. Then to reinstall I have heard of having to line up the engine. Does this require some special tool or tips to do? If maybe someone could give me a quick rundown of what is required that would be sweet! Thanks

Re: alpha 1 drive problem

Pull outdrive off "first", Upon reinstalling you'll need an alignment tool. A manual would be helpfull too.

Re: alpha 1 drive problem

Follow starsnstripers advice and get the manual. It is available online but is rather large.

Don's handy post for the manuals:
http://forums.iboats.com/showthread.php?t=251571

The basic info:
Remove outdrive (6 bolts I think)
Support the engine with your hoist. Remove rear 2 mounting bolts. Remove 2 engine side mounts. Hoist engine out. Obvoisuly you will have to disconnect all the linkages and electronics first.