1960s/1970s 4HP Black water problem

Hi - newbie - I promised to take my 2 sons fishing on a family camping trip next week. Figured we'd borrow my father's tinnie and 4HP Mercury (vintage 1970s I figure). The motor has not been run in about 8 years. It started fine in a water tank this afternoon, ran a bit smokey (but I figure that's probably bad fuel (about 3 years old mix) and a fresh mix will sort that out, BUT no water out **** hole. Stuck a wire up **** hole and got wasp mud out. Rerun still no water out **** hole. Unscrewed flush drain (small flat screw beside **** hole output on underside of cowling) and ran water from a hose into drain. Water came out the **** hole and out the centre of the prop (and a bit around front of prop) but none out what I assume is the water inlet under the plate guarded by a stainless "vent" like grill with "vanes" in the grill projecting forward (to direct water into pump??). After flushing, put flush drain cover plug back on and restarted - this time just a few drops out **** hole (and a fine jet of smoke too).<br /><br />Is the likely cause a siezed waterpump / impellor?<br /><br />Can't give much more description of the motor other than it's black, has a metal cover, has the number "40" on the front face (although definately only a 4HP and has 4HP on side), has FNR, choke lever on front, accelerator arm marked "shift" and "fast".<br /><br />Desperate to get it working to not disappoint the sons next week - any clues from this test set?

Re: 1960s/1970s 4HP Black water problem

Check that water can get to impeller and replace the impeller anyway-chances are that after 8 years standing it'll be so perished it won't last a afternoon's use even if you do get it to pump water.

Re: 1960s/1970s 4HP Black water problem

Thanks - took the leg off today and the impellor had seen better days - some "fins" just not there - a couple around the wrong way, rest brittle. I had to bust it off by prying away with blunt screwdriver (care taken to not score metal surround) - now all cleaned up. I'm guessing that the impellor will be a rubber unit that slides down over the draft shaft (long shaft remains connected to leg with spline on top) into the water pump unit and must have a hexagonal "inside" spacing that sits over the top of a hexagonal nut at the bottom of the drive shaft inside the water pump - would that be right or am I supposed to get the nut off (I think it's actually a nut that holds the drive shaft to the gear box below)?<br /><br />Also - what sort of oil for lubrication in the gearbox at foot?<br /><br />Thanks

Re: 1960s/1970s 4HP Black water problem

I think that brass nut is not a nut but the drive for the w/pump it's part of the impeller and the get stuck on the shaft, either get a new imp or find a picture of one to double ck what I've told you then you will have to split it off the shaft. Try to find a many of the imp peices as they can plug up the cooling system