Boat will not go into forward or reverse

We were out river cruising, just trickling along. Suddenly, sounds like boat revving high even though no adjustment to throttle, hands no where near! Stopped boat, restarts fine but will not go into forward or reverse gear, just neutral. Whilst in neutral can hear a pretty noisy rattling in the engine. We have recently had most engine ancillaries replaced (carbrettor, alternator amongst other things). Any ideas?

by the way, it is an OMC inboard if that makes any difference?

year would be nice. Maybe if a stringer the shafts went.

You overheating ?

We were having overheating problems in the hour or so prior to this happening. We checked the water pipe was not blocked, water coming through fine and overheating was a bit sporadic - it would get hot then cool down only to repeat the cycle a bit later on. I do not know the exact year of the boat, the BSS certificate says c1975 but some engineers who recently worked on it said they thought it may be a replacement engine as it had done so few miles for its age in their opinion. It is a petrol engine. I don't know what a stringer is so can't even answer that!

What i think you have is a electric shift stringer omc drive. You have a manual? You will have a pm in a minute.

No need to remove the entire drive.

Have a table or a large cooler or chair ready on the starboard side.

On a trailer lower the bow as far as it will go, and raise the drive 1/2 the way up.

Remove the very top bolts, and the exhaust and the lower will come down. place it on the table and tie it to the swim platform. be careful of the cable don't pull on it plenty of play in the cable.

remove the 4 bolts facing u in the upper drive from the bottom and the whole water pump and shaft will come out. you could raise the drive a little more to make it easy, i sit on a milk crate when i pull the pump.

Now you can see if the shaft splines went.

Do not buy anything yet ! Post back what you find.

Understand ?