70ish Merc 98 Cooling problem

" Hi Guys,
I have a 9.8 Mer

" Hi Guys,
I have a 9.8 Merc made in the 1970's and am having cooling problems. The pisser was letting out steam so I assummed it was an impeller problem. The impeller looks good and everything looks clear. I can blow thru the upper block tube and it's clear. I find it difficult to blow thru the pump outlet tube to the block however. Is there a thermostat in the block that would restrict flow until the head warms up?
We have no merc dealer in our little town anymore, but I managed to source out a new impeller and the tube seals for the pump intake and outlet.
I would appreciate any insight you might have.

Thanks,

Barry "

"Barry,

There is no thermos

"Barry,

There is no thermostat in your cooling system. You should not notice any resistance when blowing through the water tube from the pump. There is something clogging your cooling system. It may be some debris at the top of the water tube. You can try inserting a length of stiff wire into the tube. Sometimes this will dislodge any debris in the tube or at the base of the powerhead where the top of the tube is located. If this doesn't help you will have to start taking things apart in order to find the problem. The most common locations for a blockage are the base of the powerhead and the exhaust plates.

"

" Tony,

Thanks for the

" Tony,

Thanks for the info and quick response, I'll check that out and hopefully I won't have to rip the thing apart. I've never done this with a Merc before so not sure what kind of job it is to take the powerhead off. There's a first time for everything though, right?...laughing.

Thanks Tony,

Barry "