1983 Evinrude 90hp slow cranking

TBone78

Recruit
Joined
Nov 23, 2018
Messages
2
I’ve got a 83’, 90hp V-4 that has been sitting up for a year while restoring the boat it is on. When I tried to start it recently it turns over very slowly and will not start. Tried several different batteries to make sure it wasn’t just a weak battery to no avail. With spark plugs out it will spin over fine, but with them in it barely turns over. I also tried to spin it over with a pull string off the flywheel to see if it might be the starter and found it very difficult to turn over that way. Could the engine just be gummed up due to sitting up for for a year? Thanks in advance for your help.
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
36,047
Steps to do.----Remove lower unit and test again.----Inspect battery cables for internal corrosion .-----Remove starter , take it apart.----Test ohms from commutator to the shaft on the starter.--Should read infinity.------Replace brushes just $ 5.00 is what I get them for.---Any other history on when the motor ran last ?-----Compression test done ??
 

interalian

Commander
Joined
Jul 23, 2009
Messages
2,105
Good tips. I'll add:

-Whilst cranking the motor, measure for voltage drop between the battery negative post and a good ground on the block. If more than 0.2V, suspect the cable or connections. Remove, clean and re-fit the ground stud, ensuring it is adequately torqued.

-Repeat for battery positive post to hot side of solenoid. Again, more than 0.2V across the cable, suspect the cable or connections.

-Then repeat from battery positive to the big red cable on the starter. A larger drop here is OK due to the solenoid contacts, but if too large, suspect the solenoid contacts and/or the cable from it to the starter.

-Cables with internal corrosion will get warm after long cranking attempts.
 

TBone78

Recruit
Joined
Nov 23, 2018
Messages
2
Thank you both for your help. I will try to drop the lower unit next weekend and see how it does. The motor had not run for two or three years when I bought it a year ago. The day I brought it home it started fairly easily and I let it run for several minutes in a drum full of water. I used ethanol gas and didn’t run it dry before starting the boat restoration which has me wondering if that may have contributed to or caused my issues. Just seems coincidental that I would develop starter issues while it sat up. It acts like compression is too high and the starter can’t get it spinning over fast enough, but I can’t imagine what would cause something like that.

I will update after I get back into it. If you have any other pearls of wisdom I am all ears and appreciate any advice.
 

oldboat1

Fleet Admiral
Joined
Apr 3, 2002
Messages
9,598
A shortcut would be to jumpstart the motor from your car or truck (engine running in the car or truck). Positive contact is the post on the starter. Negative contact is the bracket. If the motor turns over well (200-300 rpms -- pretty fast), you can conclude the starter is good and the motor can turn freely. If you know your boat battery is good, suspect corrosion issues in the starting circuitry.

Wiggle the main battery wires, and see if you hear some crunching (If so, replace the wires.) Use sandpaper on all connectors starting with the battery connectors. They must be shiny for the best connection.

If you get it spinning, do compression and spark testing using a screw-in style compression tester and an open air adjustable spark tester. And if you drop the l.u., you might as well replace the impeller.
 

Bosunsmate

Admiral
Joined
Apr 7, 2012
Messages
6,129
Id go with what Oldboat says and jump from your car, i do this the whole time and you get a dependable amount of power to try the starter doing it that way.
Mine sometimes takes a while to get started when its being in storage and from there on in it starts instantly even though ive changed nothing, sometimes electrics have a world of their own.
The ends where the cables attach to the metal battery connectors is where i find the cables are most likely to fail so i remove about two inches and reattach to a new crimp connector
 

wannabewelder

Seaman
Joined
Aug 10, 2018
Messages
71
Is the battery CA high enough and is it the same battery (auto/marine)? If you do boost off a car then make sure the boosters are heavy enough to handle the current. 9/10 need brushes and head bushing and it costs nothing to have a look inside for peace of mind.
I've had brushes/bushings and bad batteries/ terminals cause the same issues you are having where it will turn with plugs removed. MCA is not CCA.
 
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