Engine bogs down an locks up

[TxGent40]

Have a 86 merc 90hp inlijne 6. Can start it up an get going full throttle and after 30 secs it starts bogging down to point of seizing motor up if ya don't turn of the key. Then it won't turn over till it's sat little bit then runs rough for a bit an smooths out and ya can take off and does the same thing all over again. Thanks for any help!

 

[flyingscott]

Replace your waterpumpj before you do any more damage.

 

[TxGent40]

Even if water is coming out of the telltale hole?
can it still come out there and still not make it up into the motor to cool it? Shouldn't that make my motor overheat alarm go off? And if so I guess it's not working cause it never went off.

 

[TxGent40]

Thanks for info flyingscott!

 

[flyingscott]

TOP motors should have their pumps changed every 2 yrs.

 

[Faztbullet]

If it has done this several times the damage is done...just a matter of time when it (motor) fails. Impeller replacement is too late.

 

[TxGent40]

About 4 trips outta 8

 

[TxGent40]

First 4 or trips out were fine then the last 8 trips out half the time it happened an trolled back. Guess change it an see how long it last.

 

[TxGent40]

Guess first do a compression check? And go from there?

 

[racerone]

What oil and fuel mixture are you using ?

 

[TxGent40]

Quicksilver oil in the injector. Have had some say get rid of it and some say keep it cause it doesn't foul your plugs like running 50:1 mixture

 

[flyingscott]

Do you have the external autoblend system? If you do get rid of it and run 50-1 mix in it.

 

[racerone]

Agreed-----Throw that auto blend away as far as you can.-----Now do a compression test !-----50: does not foul plugs on a properly tuned engine.----Not sure where that idea comes from.