'84 Merc. 150 doesn't crank.

MAtkins

Petty Officer 2nd Class
Joined
May 20, 2013
Messages
136
I've got a Mercury 150 XR2 Ser. #6532700

I ran this boat about 2 months ago and have been having trouble with it idling right but the starter was cranking just fine.

Now it won't crank.
I can hear the solenoid click and I tested voltage to the + lead on the starter.
When I turn the key to crank the motor I'm getting full voltage to the starter.
I don't know for sure what the ampacity is but I don't have any reason to think the necessary current isn't available.
I checked the battery and it's fine.
In fact I've tried 2 of them and tested the charge using a battery charger, they're fine.
The main wire from the battery to the starter is #6 stranded wire. The connections are solid.

The starter doesn't do anything.

I have noticed when it did start that it would crank for a second or so and then stop.
I could never get it to just keep cranking the motor like a car starter would.
Is that normal or is it an indication of a bad starter or something else??

Is it plausible that the problem could be anything other than a bad starter?
 

Barnacle_Bill

Admiral
Joined
Feb 8, 2004
Messages
6,469
Re: '84 Merc. 150 doesn't crank.

You can pinpoint the problem by doing a voltage drop test. There is a video on u tube that show you how to do it.
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
28,580
Re: '84 Merc. 150 doesn't crank.

Gee, does the starter turn using your fingers? Does the motor turn using your hands? If so, jumper from the battery cables directly to the starter. If it doen't turn, it is likely to have an issue (bad brushes?).
 

MAtkins

Petty Officer 2nd Class
Joined
May 20, 2013
Messages
136
Re: '84 Merc. 150 doesn't crank.

I used jumper cables connected directly to the + & - of the battery.
I connected the - to the - terminal on the starter.
I touched (and held down) the + cable to the + terminal on the starter.
The starter didn't react at all.

I can turn the motor freely but can't get seem to turn the starter.
 

spookfreak

Recruit
Joined
Nov 3, 2013
Messages
2
Re: '84 Merc. 150 doesn't crank.

Check the fuse holder near the bottom of the starter. Its an inline wired kind.
Is your kill switch activated. Ive done this on accident.
use some white grease on the starter gear shaft (it has to move freely when it goes up)
FYI I try to start motor every week or so if you can. My 84 150 black max likes it when I run it. Keeps the juices flowing. If you know what I mean.
 
Last edited:

JB

Honorary Moderator Emeritus
Joined
Mar 25, 2001
Messages
45,907
Re: '84 Merc. 150 doesn't crank.

The negative cable is the source of far more failures than the positive cable. Take the ground cable off and scrub it shiny, then reconnect.
 

Dukedog

Captain
Joined
Oct 6, 2009
Messages
3,496
Re: '84 Merc. 150 doesn't crank.

I used jumper cables connected directly to the + & - of the battery.
I connected the - to the - terminal on the starter.
I touched (and held down) the + cable to the + terminal on the starter.
The starter didn't react at all.

I can turn the motor freely but can't get seem to turn the starter.

Doin' this and ya got nothin'. I'd say tha starter is bad..............
 

MAtkins

Petty Officer 2nd Class
Joined
May 20, 2013
Messages
136
Re: '84 Merc. 150 doesn't crank.

Thanks Dukedog. That's what I came up with.
I ordered a starter. We'll see what happens after that.
 

MAtkins

Petty Officer 2nd Class
Joined
May 20, 2013
Messages
136
Re: '84 Merc. 150 doesn't crank.

I got the new starter and installed it today.
The problem was the starter. It cranks just fine now.

Thanks for all your help.
 
Top