overheating

[bandb]

I hope someone can help me. I have a 1986 34 #253. I recently changed the impeller and now everytime I sail or Motor sail for some reason the hose from the thru hull to the impeller empties its water and does not refill causing overheating. the strange thing is that i can motor all day and never have any poblems. When sailing i am sure i have never heeled over enough to expose the thru hull. has anyone experienced this if so how did you remedy it   thanks       Billy

[Lance Jones]

Hasn't happened to me. However, did you remove the strainer to clean or empty? Sometimes the gasket there fails and causes the contents to leak out.

[Stu Jackson]

1.  Lance's idea is a good one

2.  When you replaced the impeller, did you check to see that the faceplate for the pump was not scored?  A completely flat faceplate is needed.  Either sand it down with fine wet sandpaper, or buy a new one.  I've gone through three of them.

3.  Like Lance's idea, is your thru hull clear?

4.  What happens when you first come to the boat?  Is the raw feed line full of water and you can start your engine?  Is it only after sailing a while that it dries up?  I'm not clear on how you get your raw water going again when you get your engine started again.

[Ron Hill]

ban : Your new problem is simple - you have air coming into the raw water line between the thru hull and the raw water pump and the "prime" is syphoning out! 
It could be a poor hose clamp or most likely a leak in the raw water pumps' face plate.

Check these out!  A few thoughts