Engine cooling seacock is gettig hot!

[Vega1447]

Hi all.
My old MD6A is giving me grief again.
There is a lot of waterweed on fresh water lake that I sail on - it is
intermittently blocking my engine cooling water intake - a
grille/horizontal grid on port side below water level (obviously).

The engine only puts out a small amount of cooling water with exhaust
and tends to overheat - I find it hard to get above 4 knots without
engine temp exceeding 90 centigrade..

Two observations:
1) seacock for cooling water intake is getting hot as engine warms up
(say 70-80 centigrade)
2) thermostat is missing from housing but there is a piece of metal
blocking the hole where it should go.

RE 1 - am I right to infer that the brass seacock is hot because the
water pump is applying a lot of suck to a partly blocket input and
this is generating friction???

RE 2 - should I drill out the hole to improve water flow.I intend to remove and clean exhaust manifold but the above have
puzzled me..

Thanks for any advice,

John

Vega 1447 Breakaway

 

[rchrdcoe]

-John-
I dont understand how the intake seacock could get hot. Suggest you
inspect closely the path of the plumbing to insure that it is hooked
up properly. However I would definately remove the blockage where
the thermostat goes. Also , my boat has the seacock on the starboard
side. Did somebody move it?
Richard V1812-- In AlbinVega@yahoogroups.com, "John" John.Kinsella@... wrote:

 

[Vega1447]

Yes stb side of course - I was looking aft and swapped sides...

My theory re intake seacock is that cooling water pump is creating strong
flow through narrow (blocked) inlet hence heating?

Water is very poor conductor of heat so unlikely that engine heat is
diffusing back to seacock??

Only other possibility I can think of is that back pressure from exhaust
manifold (no doubt partly blocked ) is creating backward flow against pump
direction??

Thasnks for tips..

John

On Wed, 28
Jun 2006, Richard wrote: