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7 . 5hp older meccury tell tale

T

tazz11s

New member
Hello all.

New to site.

Have a 7.5 Mercury 2stroke older model.

From.old mates shed ... freebie.

Starts AOK

Had been in storage 5 + years.

Took leg off ..shaft was corroded at impeller.
Brazed and lathed it and filed new flat for lock key.

Back.together ....low telltale spray of water. When in a water drum.

Took silver screw out for flush attachment and good flow out of its threaded hole then when running.

Drilled a 1/8hole in centre of it and put back in.

Now has a good squirt out when running.

Q) shoud be ok to do this?

Assume as was pumping well is a useful fix?

Comments appreciated..

Nick Aussie
 
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There is a plastic washer at the TOP of the water tube.-----On severe overheat this plastic washer melts.----It block water flow.-----And in a test bucket the water level must be 6" to 8" (20cm ) above the impeller.
 
The flush screw is for flushing the motor with fresh water after running in salt water, drilling a hole in it has lowered the pressure of the water flowing to the powerhead - like a leak. Plug the hole, look on the port side of the engine below the cowling for the tell tale water when engine is running.
 
Quicksilver said:
The flush screw is for flushing the motor with fresh water after running in salt water, drilling a hole in it has lowered the pressure of the water flowing to the powerhead - like a leak. Plug the hole, look on the port side of the engine below the cowling for the tell tale water when engine is running.
Click to expand...

thanks for reply..

The telltale had a flow for a few minutes with new impeller repair then stopped pretty much to a dribble so I thought maybe impeller failed.

The drilled flush screw has a good pumping flow.

So does that mean impeller is actually running pumping ok?

Is the telltale maybe just a small hole upstream of same flow line ?

Cleaned telltale with wire.

thanks..
 
Yes the pump is working but losing pressure thru that hole in the screw. the tell tale shows that the water is flowing thru the block.
 
Quite possible the tell tale is blocked, make sure it’s cleared, strimmer cord is good to use, push some in the tell tale with the engine running . Likely the new impeller has pushed water with some debris in it round the engine and blocked the tell tale exit.
 
Did a air blowout and strimmer pull though holes .
Cleared tell tale and yes got a good flow.

I filled the test hole in screw plug.
I reckon that screw plug and tell tale likely same internal flow tube .
Are only 1 inch apart.

Was a major repair .
Shaft been patched before years ago.

Hardest part was releasing prop end screw retainer.
Made a tool that fits 4 notches in aluminium ring.

See if repair lasts.
No water seems to be in gearbox when check drain.

Motor starts with about half a cord pull.
Thanks for info all.
 
tazz11s said:
Did a air blowout and strimmer pull though holes .
Cleared tell tale and yes got a good flow.

I filled the test hole in screw plug.
I reckon that screw plug and tell tale likely same internal flow tube .
Are only 1 inch apart.

Was a major repair .
Shaft been patched before years ago.

Hardest part was releasing prop end screw retainer.
Made a tool that fits 4 notches in aluminium ring.

See if repair lasts.
No water seems to be in gearbox when check drain.

Motor starts with about half a cord pull.
Thanks for info all.

On tinny boat ready for a run now..

The above idea of removing flush plug to check pump impeller flow might help others with blockages I reckon.
Click to expand...
 
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