95' Mercury Force two-stroke cooling problem

[capeape56]

My 40 HP Force 2 stroke does not have water flow. It was spitting some last fall when I bought it, so I did an impeller change thinking that would solve it. No luck this summer when I tried it and it heated up pretty quick - no water flow at all this time. Let it cool down and restarted it - don't think I hurt it much. Pulled the lower leg and the impeller looks fine, still like new. Blew some air up into the pickup tube to the head and could hear air blowing out freely inside but nothing coming through the outlet. Is there a connection to the cooling passages that may have come off or is wasted, either at the pump discharge or at the top where it goes into the block? Maybe a blockage or a thermostat issue? Please help.

capeape 56

 

[bentle]

Re: 95' Mercury Force two-stroke cooling problem

Could be thermostat but even closed it should let some air through. Could be pluged up
behind it or before it. Before getting into that area I would drop lower leg and see if the
Water pickup tube is making a good seat into the pump housing. There should be a plastic fitting
thet seals the tube up tight so as to prevent water from running out around the sides of the
Tube. Could be rubber fitting as well. Check the little key way that fits inside the impeller is
fit against the drive shaft and also not sheered off. Water pump housing must have gasket between lower leg and pump housing. If the impeller is unable to get water flow up to the motor
then you will over heat and that can and will lead to bigger and more expensive prob.

 

[capeape56]

Re: 95' Mercury Force two-stroke cooling problem

Thanks Bentle. It was suggested that getting the key lined up properly in the impeller is a bit tricky so I'll check that first as well as the fit into the tube and the thermostat.

capeape56

 

[bentle]

Re: 95' Mercury Force two-stroke cooling problem

While you have your lower leg off, it might be a good idea to remove thermostat and then take
your garden hose end, put it up to the motor where thermostat seats and flush out any material
That may be clogging open water way passages in motor. Do not run motor at this point. Remember that you can cause internal motor damage by over heating within 30 seconds. Parts for now are plentiful but not cheap. Most parts I should say.