Something went bang??

[Waterman]

While out on the water last week the starboard engine suddenly over revved so I shut it down. I thought it might have been the rubber hub on the prop that was slipping so came home on one engine. When I dropped the lower leg there was something extra attached to the drive shaft .. Anybody tell me what Ive broken?? Engine is a 2000 mariner 2 stroke (2 cylinder) model.
The piece in the pics is what i pulled off the top of the drive shaft. It came off fairly easily but the cam shaft end looks to broken/snapped??

[ashbypower]

Is it an Ex RNLI Engine??

[Waterman]

Possibly??

What difference would this make??

[doggypaddle]

It just looks like a shaft extension piece. could be genuine part or a piece from one of the "shaft extension kits" you can buy for most engines.
Is the leg one piece or is there an extra bolt on piece the same length as the extension that shaft provides?
I am sure someone who knows the particular engine better than me can tell you if its a genuine factory part or a piece from a kit.
Your next problem is getting the broken stub out of the crankshaft end, it may well be very tight due to it being twisted, you will probably need to drop the powerhead off to gain access, and maybe drill it right through and tap it, so you can either wind a bolt through to jack it out, or attach a slide hammer. if you're very lucky there may be enough poking out to grab it with a pliers.
the next question is why did it break. is the gearbox free to turn did you hit something? any damage visible on the prop?

[Nasher]

Doggy-P beat me to it.

It does look like a shaft extension, and the rest must be stuck in the end of the crankshaft.

Nasher.

[Waterman]

Cheers guys,

Have no idea how it happened?? Didint hit anything but was at WOT when it failed.

Any idea how one would go about identifying what driveshaft extension kit would be a replacement one??

[uncle al]

hi your obm is an ex R.N.L.I. obm and the part number is RDG3952 which can be ordered from any Merc/Mar dealer my phone number is 01869 326411 during office hours only

[doggypaddle]

Originally Posted by uncle al

hi your obm is an ex R.N.L.I. obm and the part number is RDG3952 which can be ordered from any Merc/Mar dealer my phone number is 01869 326411 during office hours only

Fantastic service from uncle al again, bet he cant get the broken piece out as easily as giving you the part number though

[Nos4r2]

Originally Posted by doggypaddle

Fantastic service from uncle al again, bet he cant get the broken piece out as easily as giving you the part number though

Hopefully the splines aren't as twisted at the end of the crankshaft of it may be an engineering shop job to remove it.

You'll want to investigate the gearbox too-it's taken a lot of force to do that damage!

[Bigmuz7]

Another vote for twins then