evinrude 1985 150 hp model j150txcos compression

[lior]

Hello everyone.
I am looking to purchase a boat with this engine on it
the engine did not run for 3 years, i run it for 20 minute and did a compression test, all the cylinders read 70 psi.
is that a good reading or the engine is toast.
the other issue is when i start the engine it will idle at 900rpm for 5 minute and suddenly will jump to 2000 rpm ?
any help will be appreciated.
Is an overhaul on this engine hard to do?
thank you for any help

 

[Joe Reeves]

Re: evinrude 1985 150 hp model j150txcos compression

the engine did not run for 3 years, i run it for 20 minute and did a compression test, all the cylinders read 70 psi. is that a good reading or the engine is toast? the other issue is when i start the engine it will idle at 900rpm for 5 minute and suddenly will jump to 2000 rpm? Is an overhaul on this engine hard to do?

Sitting for 3 years... the carburetors are no doubt fouled, clogged, gummed.

A 70 psi reading could be due to very slow cranking or a bad gauge... remove all s/plugs and try a different gauge. PSI should be approx 100+ psi.

RPM's jumping from 900 to 2000 is not good. Overhauls are time consuming and expensive, and often a waste of time.

 

[lior]

Re: evinrude 1985 150 hp model j150txcos compression

Thank you Joe.
i try 2 set of gauge for the reading both came out at 70 psi.
the carb were empty when i got the engine it was store at offshore marina.
there is a little bit of oil coming out from the exhaust hole just above the propeller when the engine is running..
i dont know were to look for the idle issue is altitude as to do something with it.?