How can I tell if the used outboard motor I'm buying is in good condition?

Question

I am considering buying a 14' Monark aluminum flatbottom boat with a 20Hp Mercury Outboard Motor that was made in 1974. I would like to know what to look for when I go to check the motor out. I don't know anything about boat motors, so anything you can provide would be helpful. Thank you! ~Chris

Answer 1

first i would loosen the gearcase drain slightly it is a little screw on the bottom of the foot
if water comes out or the oil looks milky don,t buy it
if it looks clear or dark it is probably ok

look at the engine if the paint is peeling or peeled around the head it has been run hot don,t buy it
if the paint looks ok just faded it is probably ok
see if you can do a compression test
if you can make sure the readings are around 10 psi of each other

have them crank it if they crank it without water don,t buy it
if they put the muffs on does it sound ok

if you do get it plan to do a tune up
have the gear oil changed
and replace the water pump

Answer 2

This Site Might Help You.

RE:
How can I tell if the used outboard motor I'm buying is in good condition?
I am considering buying a 14' Monark aluminum flatbottom boat with a 20Hp Mercury Outboard Motor that was made in 1974. I would like to know what to look for when I go to check the motor out. I don't know anything about boat motors, so anything you can provide would be helpful. Thank you!...

Answer 3

Buy Used Outboard Motors

Answer 4

A 1974 Merc under any conditions is in the geriatric category for outboards. 2 cycle engines can go forever, but eventually die from corrosion, especially if used in salt water. You can have the motor inspected, test compression, etc. just like a car engine, but figure that it's due for a major overall, especially ignition parts and water pump. All in all, if it runs, pumps water, doesn't have obvious corroded parts, it probably will push the boat for a long time...... but don't expect it to be reliable. I'd be sure to always take a small kicker to get home with, just in case. Even a 2 1/2hp engine would serve that purpose.

For reference, if it doesn't run, change the plugs before you do anything else.

Answer 5

you'll have to re-power, figure it will cost about $100 per horsepower, a 20 H.P costs about $2000 new, Chris, that engine is worth about $1.50, where are you going to get parts from ????? 1974 ? If you like the boat, buy the hull, ANY boat is worth only what the motor is worth, most hulls are not worth much money, in the world of "BOATS", it's all about the "motor", any out board is not worth much after 10 years of service, I wouldn't buy a used boat with a motor older than 3 years, when looking at any boat with an outboard, ask to see the maint. records for the water pump being changed every two years minimum, that will show a good service record, as it is the weakest link on an outboard, tired water pumps make engines run "HOT" and lower their life expectancy. If the owner tells you that the water pump does NOT have to be changed out every two years, walk away from the deal.

Answer 6

Chris,, take it out for a ride ! or,,,,have a mechanic that is willing to go with you ..no !,, take it for a ride ,outboard engines need to be ran!! put it to the test ,run it for at least 20 ,minutes or more ,and not in a tank ,put it under a real load ,give it hell,if it blows up, do not buy it ,ha! seriously there is no real way to be sure other than a real trial .when you get back in make sure the gear case oil is not milky looking (no water in the oil of gear case ) ok.... good luck,old boat motors that have been taken care of are like old Harleys

Answer 7

First thing to do is a compression test. If all the cylinders are close to the same reading you should be in good shape unless the readings are all low. Ask if it has been run is salt water very much, if so, leave it alone, too many years of salt build up will be nothing but trouble. If it runs good, doesn't smoke bad and the compression is good, it should be a decent engine. Parts are available on-line for those older engines and some dealers still carry them also......good luck!

Answer 8

i bought recently a suzuki DT 7.5 YEAR 1977 -79 2CYLINDER 2T but engine takes a few time to start needs to warm up and when try to start while its on neutral gear propeller turns arround, i chanched the plugs and the oil in gear case was black colourso i chanched that also now it worries me the transmission if its brocken?

Answer 9

get someone you know who can look at it with you. I had a late fifties 35 johnson that I bought in 1980 and it still runs fine.