Mercury 3.3hp 2 Stroke - No water through Tell Tale.

[lustyd]

There must be places where the water is near to the exhaust right where the tell tale is. In theory you could test this by injecting gas into the tell tale and using a gas detector in the spark plug hole, or blow air into the spark hole and see if it comes out of the tell tale. May have to tape off the other known holes.

 

[BillBudd]

I think I must have brought @Polybus's outboard. Actually mine is a Mercury 3HP (HB3) but seems to have exactly the same problem - although I read Polybus's entire PhD thesis rather than doing ALL those tests myself. So now I'm going to take up where he left off except I AM NOT A QUITTER

So brought this about a year ago and guy said it wouldnt start but wasnt siezed so purchased it for $90 after some haggling. Put some new fuel in it and looked at the spark plug and it started first pull. Scared the bejesus out of me but unfortunately no water from the tell tale. Runs well and sounds nice and quiet compared to a couple of 5HP Mercurys I have so would love to get it running as lighter for a 14ft sail boat I have.

I replaced the impeller and greased everything I could touch but no tell tale. Took the leg off but unfortunately couldnt remove the gear box as the fwd bolt broke and I'm not game to drill it out just yet as in a difficult position to get the drill straight.

When detaching the leg from the powerhead I saw all the water channels were blocked with salt. Cleaned them all out and blew out the water outlet tube coming from that using an air compressor which produced a clear air flow from somewhere within the impellor housing. Put everything backed together and started in a bucket but again a complete Polybus result with no tell tale.

So dissembled again and impeller seems good as was liner etc and no water in the new gear oil. I did then find the rubber tell tale hose which is attached to a vent in the bottom/side of the powerhead was completely blocked and so was the vent itself. Removed hose and cleared both the hose and the vent (again full of salt) and then blowing the vent with air produced a good air flow as witnessed from plenty of bubbles from the bottom of the leg in the bucket and the outboard fully assembled (except left the cowling off).

When runing the engine (briefly) I did notice a small amount of exhaust coming from the vent where the tell tale hose is inserted so think I have the same problem as Polybus but unfortunately no where near his experience so really appreciate any tips from the legends on this forum.

I do like the theory that exhaust is somehow preventing water flow but also read somewhere that with small outboards the exhaust is used to aid water flow from the tell tale? The gasket between the power head isnt in great shape but this and head gasket/milling etc didnt seem to make any difference for Polybus so wonder if anyone had other ideas for me to test.



PS everything Polybus said above about Australia's pandemic response in 2021-22 is now widely accepted to be true - so to Polybus!