Dear all,

I have a Mercury 4 hp 2-stroke, assumed to be from 1990, which has a
problem since I used it for a longer trip on my 17 ft sailboat.
After having run for a couple of hours the tell tale flow became quite
weak, the engine still ran but the temperature seemed to become somewhat
higher than normally when I use it just to get out or in the harbour. I
tried to suck on the tell tale hose and there was a high resistance to
get some water through it.

My assumption is that there is an issue with the impeller. Is there
anybody experienced enough to describe the impeller replacement
procedure or even can provide a kind of maintenance or repair manual?

Any help is highly appreciated.

Regards,

Peter