Took th e boat out today for the first time this year. ( work and projects at home have not allowed me to get it out before today.)
Was on the water about 10 minutes and after making sure everything was OK in the engine compartment ( looked for leaks, noises, smells, everything was good, guages were normal.)
Went for a run upriver at Hardy pond and was cruising at about 4000 RPM ( 5400 is max) when the boat suddenly kind of slowed but the engine didn't rev. I drive with hands on the throttles at all times. Backed off to idle and neutral.
Port drive wont move the boat. Starbord is normal.
fininshed the day slow on one drive.
Got home and pulled the top cap. No metal, normal smell.
If I turn the prop it turns easy with no noise but then it gets stiffer at one point and the center shaft ( cap removed) moves a little.
OK what happened?
Did I break the vertical shaft?
Blow the bottom gearset?
Help I want to go to HOT BOAT next weekend.
I have a call in to Mr Gadgets.

Bravo 1 ?

Yes They are BRAVO 1's with IMCO 2inch shorty lower cases and vertical shafts.

Flywheel coupler went would be the first thing I would check. To check you'll need a load on the prop so with the boat in the water and in gear look between the engine bellhousing and transom and see if the drive input shaft is turning with the engine. If bad the engine will need to come out to change.

I don't think it was the coupling since I didn't smell any rubber. I will pull the drive tomarrow.
What I don't like is with the drive in neutral the prop doesn't rotate smooth all of the way arround.
Why isn't the vertical shaft turning constantly when I turn the prop?

i have seen the splines at coupler between upper and lower shear, sounds like that.

Well I found out what happened.
The only part not Mercruiser.
IMCO vertical shaft.
broke right above the bearing just above the lower gear set.
No metal in oil and the bearing races don't show any wear or damage.

I think it is time to upgrade to 1.25 inch prop shaft.

Does this look like it was cracked for a while?