Yamaha Pro 50 Intermittent Starting problem

scotttaylor

Cadet
Joined
Apr 25, 2005
Messages
10
Hello

I have a problem with my 1989 Yamaha Pro 50 outboard and I am looking for any help that I can get.
The problem is that the motor will randomly just not do anything. Yesterday I was out on the lake and the problem occurred again. After fishing all morning and attempting to head in I went to crank the motor and nothing. It acted like a blown fuse. (Which it wasn?t) when I turned the key over I heard the motor attempt to turn over for about a nano-second. (Similar to when you blow a fuse) I checked an inline fuse that had previously blown and it was not the problem. This is not the first time that this same exact scenario has played out. In previous scenarios the motor eventually fired right up and I hade every reason to believe that this time it would do the same. One other thing to mention is that the tilt and trim will not work either, not on the motor or the controls. I tried disconnecting the positive side of the battery and re connecting it to no avail. I then messed with the tilt and trim at the motor and could hear what sounded like some electrical arching but it was very faint. I then disconnected the negative side of the battery and re connected it, tried the tilt and trim and it worked. I then tried the ignition and the motor fired right up. If I had to apply what little knowledge I have regarding the issues I would guess that I am having a solenoid problem. I would appreciate any help or guidance the one can give as it is my assumption that at some point the problem will no longer correct itself and I will be stranded on the water.
Thanks in advance.
 

99yam40

Fleet Admiral
Joined
Sep 7, 2008
Messages
9,208
Re: Yamaha Pro 50 Intermittent Starting problem

Sounds like a bad connection or cable. clean all connectors, battery and the other ends also. Take them apart clean and apply some grease to keep corrosion down, and make sure you torque them properly.
A voltage drop test while problem is occurring will help pin point where the problem is located.

I have seen the problem inside the cables also, where the battery terminal connector mates with the cable, sounds likely in your case.
 

hawkman-1

Cadet
Joined
Jul 18, 2010
Messages
12
Re: Yamaha Pro 50 Intermittent Starting problem

I just had the same problem. All parts tested ok sanded all terminals still nothing. Turned out the batt cable was corroded on the inside on the batt. end. I cut it back
6-8" untill I found copper and that was it.
 

scotttaylor

Cadet
Joined
Apr 25, 2005
Messages
10
Re: Yamaha Pro 50 Intermittent Starting problem

Thanks for all of the tips. I will replace both positive and negative cables and see it it still occures.

Thanks Again
 

JB

Honorary Moderator Emeritus
Joined
Mar 25, 2001
Messages
45,907
Re: Yamaha Pro 50 Intermittent Starting problem

Starter circuit corrosion is the most common fault this time of year. It should be part of the Spring prep to overhaul all high current circuits.
 
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