1998 mercury 15 hp

[tropical_2000]

hey guys
I need a little help
thinking on buying a 98
15 hp mercury for a kicker on my boat
my question is how can I perform a compression test
this outboard is a manual start
I have only done compression test on electric start
for those of you who have had experience with this type of outboard
like to hear the good and the bad
and one last ?
the price is $ 900
is that a good price

thanks in advance

 

[emckelvy]

Re: 1998 mercury 15 hp

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[emckelvy]

Re: 1998 mercury 15 hp

Howdy,

The way to do a compression check on a manual-start outboard is to remove both spark plugs; make sure the kill switch is "off" so the ign won't spark (or if it has no kill switch, stick the plugs back in the spark plug boots and ground them).

Then insert compression gage in the cyl being tested and 'rope' the motor over with the recoil starter until the reading on the gage stops rising. There's your maximum compression. Shouldn't take more than about 4-6 pulls to get there.

Repeat with the other cyl and there you have it. Readings on a very good motor would be within 5 psi of each other. More than 10 psi diff I'd start worrying.

It might just be carboned-up piston rings which would respond to a decarbonizing agent like Seafoam, but you never can tell and it might also be bad rings or scored cylinder.

Regarding pricing, huge variable is condition. If this motor is clean enough to eat off of, and runs like new with perfect compression, maybe. Otherwise pretty $pendy.

For an excellent baseline on motor prices, check the classified ads in the "boats" section of your local www.craigslist.org

As true an indicator of market values as you're gonna find. And who knows, you might find a better deal on a motor there!

HTH.............ed

p.s. plan on changing the impeller on any used motor you buy, unless it's been recently done. Better than than burning up your 'new' motor!

 

[tropical_2000]

Re: 1998 mercury 15 hp

emckelvy
thanks fot the reply
your info is just what i was looking for

insert compression gage in the cyl being tested and 'rope' the motor over with the recoil starter until the reading on the gage stops rising. There's your maximum compression. Shouldn't take more than about 4-6 pulls to get there.

and as far as the price goes
gonna try to deal
I have only seen pics so far
but if the compression checks out ok
and the outboard runs smooth
and is really clean and in good shape
I think the price is ok
craigslist what a great site
I agree
cheers