Help/Advice with buying used Astro w/115HP Merc

[PaulAlford]

I am looking to purchased a used 1994 Astro boat with a 115 HP 1995 Mercury outboard on it. Both are in decent shape. Engine has been sitting a while, not used much. It started right up, idled fine, rev'ed up fine, smooth, shifted into forward and reverse with solid clicks into gear, trim and tilt is fine. The only thing I noticed was the water discharge was about half of what I thought it should be. Pretty slow stream and pressure, but he did admit the waterpump hadnt been replaced since he had it (2 years) and who knows before that so it could be just an old water pump/impeller (which I can replace.. I think since I did my current 45 HP Mercury.)

I am going back it 2 days to put it in the water and plane it and let it get up to temperature... but is there any other simple advice or simple things I can do to check it out before I buy it ? I am a novice and NOT a mechanic.

Thanks in advance and please hurry with some ideas.

Paul

 

[RLT III]

Re: Help/Advice with buying used Astro w/115HP Merc

with the impeller that old your risking failure and overheating on the test ride and would imagine with the knowledge of your current merc you can determine a good buy a good sounding engine.

Compression check is a good idea and or even to look at the gear oil others may have some other suggestions

 

[CharlieB]

Re: Help/Advice with buying used Astro w/115HP Merc

I completely agree, a compression test is MANDATORY, a Spark Test can be done during the Compression test so you call know the the ignition system is functioning correctly.

Ditto checking gear oil.

If the owner is willing, disconnect the fuel line after the fuel pump and check flow while cranking, any weakness in the fuel stream pulse will cause a melt-down at WOT.

Change that impeller as soon as you buy the boat and get it home.

 

[PaulAlford]

Re: Help/Advice with buying used Astro w/115HP Merc

Thanks for the ideas guys. With this water stream being half of what it should be... am I assuming correctly that it is more than likely an old impeller ? Or could a weak stream be something more major hidden ?

Also, if I try a compression check, how do I find out what the compression SHOULD be ? Is there a chart somewhere ?