Older mercury 20hp isnt spitting a constant stream of water. Where to sart?

Question

When ever you rev it up at a higher rpm, a little will come out but thats it. Most say its clogged, which could be but whats the best way to clean it out?

Answer 1

get a paper clip straighten it out and insert one end in the p**s hole to clean it out and if that dont work than change the water impellor

Answer 2

If as you say,when you rev it up,some water will come out from

the tell-tail,then it is not clogged.Your impeller is either getting

weak or some of the fins could be broken off.I suggest you install a new impeller.When you are changing this be sure there are no pieces of the old impeller stuck in the housing.

Another thing to check is your housing to be sure that it is not melted from overheating because this will also make for weak

water pressure.When you have your lower unit off,blow some

compressed air back through the tell-tail,just to be sure that it

is clear.Hope this helps and good luck.

Answer 3

just to clarify...not all motors have a "telltale" -- stream of water exiting the cowling on the starboard side.  If you're looking at the exhaust relief ports (two holes back side of motor just below the powerhead), sounds normal.

if you have a taletell not peeing, stick a wire up in that nipple, see if insects are nesting up in there.  pull the hose off & flush it out.

if that don't get it going, then replace the water pump impeller.

Answer 4

I agree with jtexas.   Sometimes you have to back flush the cooling system, and sometimes you get air being sucked in to the system if your on earmuffs.  Feel the power head with the back of your hand, be careful, see if it's overly hot.

Answer 5

On old boat motors the bolts around the water pump are usually rusted in place and not worth snapping to remove.How does the water flow on high revs? The force should force water through. So as long as you just go flat out you'll have no worries.

Answer 6

Replace the impeller in the water pump. This is normal maintenance, they should be replaced every 2 years at the latest.