Mercury 4HP two stroke no tell tale

[RICK HAN]

Having replaced the impeller on a 4HP Mercury 2 stroke outboard motor, still had no tell tale water jet on starting. Used a small allen key and twisted back and forth inside the tell-tale tube. Eventually dislodged what I believe was a rather stuborn salt deposit and water jet cleared beautifully. I was suprised that it took quite a bit of steady effort to break through the deposit. Then ran Salt Away through the motor by putting in a reasonable amount of the cleaner into the recirculating water for good measure. All good. Hope this helps as removing the power head to get to the telltale would be a major otherwise.

 

[VicS]

Having replaced the impeller on a 4HP Mercury 2 stroke outboard motor, still had no tell tale water jet on starting. Used a small allen key and twisted back and forth inside the tell-tale tube. Eventually dislodged what I believe was a rather stuborn salt deposit and water jet cleared beautifully. I was suprised that it took quite a bit of steady effort to break through the deposit. Then ran Salt Away through the motor by putting in a reasonable amount of the cleaner into the recirculating water for good measure. All good. Hope this helps as removing the power head to get to the telltale would be a major otherwise.

Dont forget the tell tale is only a tell tale. The flow of water from it merely confirms that the pump is pumping water up to the power head.

What really matters is the flow of water through the engine, and that exits with the exhaust gas under water where you cannot see it!


If in any doubt about the cooling feel the temperature of the cylinder block and cylinder head.
You should be able to touch and maintain brief finger contact with any part except perhaps around the spark plug . If you cannot. or if there is any discolouration of paint or if a splash of water immediately boils off it is overheating and remedial work is required

 

[Seajet]

It's quite a simple job to remove the head and clear out the waterways; these engines are prone to salt blockages.

I put my hand under the telltale ( if there isn't one you've got an instant problem ) every few minutes, as a temperature guage.

Every winter I run the engines in oily fresh water in a wheelie bin, with the prop removed, but I take the head off and clear out the salt too before & after.

Not sure where you are but Ron Hale Marine at Southsea near Portsmouth supplies head gaskets.