Major hose leaks

[Steve]

Last summer our 97 SN lost power underway. The engine warning light came on and I shut it down right away. The problem was overheating. We bought the boat the previous season and don't know when the impeller had been changed but the fins were all torn off and things seemed fine after we replaced the impeller... except I've had problems with major hose leaks ever since. Usually the leak is at the joint between the hose and either side of the U shaped cast iron fitting below the raw water pump; the one with the small drain plug at the bottom of the U.

I've replaced the hose clamps and made sure they were tight. Interestingly, once I get it to stop leaking by fiddling with the clamps everything seams fine for several days with normal engine temperature.

Our dealer didn't think a piece of fin could have lodged downstream causing back pressure since the engine runs at a normal temperature once I get it to stop leaking.

Is this a hose problem? Do the hoses need to be replaced on a ten your old SN? Any other ideas?

Thanks,
Steve

[bchesley]

RE: Major hose leaks

I would dimantal the cooling system as far as you can to make sure there is not a piece of impeller in there. That way you will know for sure you can cross that out. Then inspect the hose fittings for corrosion. The U shaped piece is cast and can and will corrode. If you have good surfaces to mount the hose too it should not leak. Are you using a screw driver to tighten the clamp or a wrench. I screw driver will not tighten it enough for a pressure hose.

Brad

[Steve]

RE: Major hose leaks

I too still wonder about a piece of the impeller intermittantly blocking something downstream. I'll start taking apart the cooling system.

I'm using a screwdriver to tighten the hose clamps. I haven't used a wrench since I was told it's possible to overtighten the clamps and I can get them tight enough with a screwdriver to start cutting into the hose. I've worked with cooling system pressure hoses on cars in the past and never had any problems.

Thanks for the input,
Steve

[jos]

Leaks

Steve,

Use quality hose clamps. Take off the hose remove the clamp and check the area where the hose clamp sits, due to often winterizing the hoses can shear off in the clamp area. Sometimes you can take of an inch so you have a new and flexy hose fit.

Check on above from the pump back to water intake, tight all clamps. Minor vacuum leak will give no water intake at low rpm.

I have bought 2 used Nautiques and had to fix this twice.

Also the grease the water strainer very light, this will give a better fit and no vacuum leak.

Succes