Suzuki DT85 Water Pump

This afternoon I decided to give my outboard a run with muffs in the yard. The water alarm sounded initially which is normal for a few seconds until water is pumped up into the block. Problem is it never stopped sounding ! I let it run for maybe 2 minutes while I ensured that the muffs were fitting as well as possible and the tap was on full. The water pressure was good. Last time I started it about 2 months ago everything was working fine. I then filled up a plastic tank that I have, it covers the lower unit to just above the cavitation plate. (so the water intakes are under water) restarted the motor, still no water coming out the tell-tale. I guess I now need to look at the water pump impeller ? I have a Clymer shop manual for this motor (1992 model) however where it mentions how to remove the lower unit, in particular disconnecting the gear shift, it appears to be different to what I can see on my motor. It mentions getting access to the shift linkage through a grommet on the front starboard side of the lower engine cover - there is no grommet on my engine ?!! Can anyone help me here - I recall my old Mercury had a shift shaft that had splines so there was nothing to disconnect - perhaps this engine is similar ? The engine did get 'rather' warm but I could still touch it, so I am confident no damage done.<br /><br />Thanks<br />Mike