well i took my boat out for the first time its a 78 kachina w a bbf460 the boat ran great all weekend and the last day i took it out i wasnt sucking no water in through the jet just seeing what the possible reasons of why this happened

You either broke your pump shaft or you need to lay up under the boat and see what you sucked up in there

Coulda broke the drive coupling or the bolts to the crank too I suppose. My Biesemeyer 'seemed' to do that a couple of times when it was just a rock jamming the reverse bucket about 3/4 closed. Also happened on the Moo on Saturday when the bolt fell outta the reverse bucket cable, wouldn't move, the Jet would open the bucket just enough under throttle to hold it in a neutral position. Thought for sure I'd busted something important! I'd check out your reverse bucket and control lever, etc,  just to be sure.

Ray

thank you guys it does seem like it was a air pocket cause when i shut it down and started it again it was ok after a bit but my temp was rising and it started to worry me a bit but i will check all that out

does that happen very often the air pocket?

Do you have a droop ?