Keeping an engine cool

[Mark McCray]

Ok, so I thought I knew it all. Have built a few boats and never had a problem cooling off an engine before. So I built a 20 sport hydro this year and put a 20 CMB in it. Bought all the right hardware from speed master and put it together.

Take it to the pond and she wants to fly but it slows down and stops do to not getting any water. Now the rudder, line and head are all clear and when I blow through it its clear. So why won't water go through the system and out. I have no idea but the water won't go through.

Help, I don't want to burn up an engine.

 

[Terry Keeley]

Pinching the line when you put on the cowl?

 

[dave roach]

Mark

What I found on my cmb 20 that the brass water fittings when screwed in the cooling head was to long and hitting the block not letting the water to flow.

Dave Roach

 

[Chris Wood]

Mark,

Take a small little round file and file a groove all the way from the hole in the rudder to the leading edge.. if you don't do this you can get intermittent water flow.

I would also reccomend doing away with a fitting in the top of the head.. I drill a .070 hole in the head and works fine..

one other thing is to check the o-rings in the water jacket. make sure they are not messed up. if they are that caused water problems to the exit of the jacket.

hope i helped

chris