invader_1230
Cadet
- Joined
- Jul 2, 2005
- Messages
- 10
i had good luck with my last post for the manifold holes, and i fixed all that. i bought this 1968 40 hp johnson and i was told it was not run in 5 years. so i replaced the coils points etc. and got it to run and shift, after some miner adjustments it was running great. BUT there was no water pumping out at high speeds so i replaced the water pump, and am 100% sure that i did it correctly as it is the 5th or 6th i have done on similar engines. NOW heres my problem when i am in neutral or going slow the water pumps out nicely, as i gain speed more and more pumps out as it should. as soon as the boat gets on to a plane the water stops pumping. i tested to see if it had anything to do with rpm, by reving it in neutral, but water pumped out at all rpms. the boat is a 10' gw invader that has a very short transem and both water pick ups are underwater at all times.i took out the sparkplugs and they look golden brown like they should, so i have ruled out a head gasket, and the thermostat works well. i also checked the water pickups, and they were both clear. im am confused. the ONLY thing i can think of is that when i had it apart one of the water tubes was a little oval and dented around the bottom where it goes into the pump. so maybe there is not enough suction at a high speed, but that still would not explain its ability it pump water at a high rpm in neutral. so i dont really know what to do now. does anyone know what is going on?? <br />thanks
