Yes i replaced the first clip on the oil inlet on oil cooler started boat then the outlet oil pipe on oil cooler blow off so i dont think its the clips i wish it was my first thing to check was going to see if the oil cooler was blocked but with the outlet oil pipe blowing off has confused me the oil cooler is only for the gearbox the engine oil dose not mix with the gearbox oil thats why i thought i could start the boat as long as i leave it in neutral but thanks for your help i think i will have to i.d gearbox and see where the pressure valve is some one might of had the same issue i will look into the airlock thanks grahamI don't know the specifics of your engine or gearbox but being pretty old I'd start by replacing the hoses and clips - I've seen a flap form on the inside of an old hose, causing it to block. Obviously check the cooler itself isn't blocked, but that wouldn't explain the outlet hose coming off. The only other thing I think of is an airlock in the cooler.
If this is occuring with the gearbox in neutral - easy enough to check - then you can't run the engine to charge the batteries until you've sorted it (or shortcircuited the cooler)
FWIW - you'll get more quality responses if you invest in some punctuation; you're making it unnecessarily hard for people to help you