stator issue maybe??

[0rion]

I did a search and really didn't find anything that helped me much so thought I'd post up.
I have a 95 evinrude model # E50TLEOD that's blown the 25 amp fuse on the rear of the motor twice now. I haven't really traced it down to see what the fuse actually goes to but when it blows I lose power to the motor as a whole including the trim.
Today I was out fishing with my son and I noticed going across the lake the volts gauge was pegged (18+ volts). I tapped the gauge as the gauges on the boat are showing their age but it stayed pegged. We slowed down and were idling up to the place I was going to fish and right before I shut the boat off the warning buzzer kind of came on. I say kind of because it was weak and broken and not a full on buzzer. I also notice the volts had dropped to about 10v or so. When we were getting ready to leave I turned the key and nothing. The fuse was blown. I knew which one because it blew on me a few weeks ago in the back yard while I was idling the boat.
The next time I have the boat out I plan on taking my multimeter and throwing across the battery to see if in fact it's putting out over 18 volts. Does this sound like a possible stator issue or should I be looking somewhere else?

 

[NightRunner]

Re: stator issue maybe??

Looks like rectifier/regulator is bad. Stator may be good.

 

[0rion]

Re: stator issue maybe??

thanks for the reply. Anyway to diagnose it? Can I do it the same as checking the alternator on a car? I'll normally throw a volt meter across the battery terminals with the engine running and see what the alternator is putting out. Same theory? What kind of job is replacing the rectifier? I'm fairly mechanically inclined ( at least with cars). I do heads/cam, rear, and tranny stuff. I just have zero exerience with a boat. It still should all be nuts and bolts just like anything else but there is a learning curve there I'm sure. My next step is to get a repair manual for the engine. Those are usually pretty helpful.

 

[steveo32]

Re: stator issue maybe??

very simple at least for my 70hp johnson, disconnect the three or four wires and unbolt the cylynder shaped rectifier and then put the new one on. There is a post with a detailed description on how to test the rectifier somewhere on the boards.

 

[Vic.S]

Re: stator issue maybe??

There is a post with a detailed description on how to test the rectifier somewhere on the boards.

It is on the Engine FAQ board. I'd add though that if you use a digital multimeter for the testing use it on the diode test range as not all meters will work satisfactorily on all ohms ranges for diode testing.

I am not sure but I do not think the output on this engine is regulated. If I am right it will be perfectly normal for the volts at little or no load to rise way above the figures you'd expect with a reguated output.

However you would not expect anything like as high as 18V measured at the battery, or as low as 10V.

 

[ezeke]

Re: stator issue maybe??

The rectifier may be bad, but it is unlikely that it is the cause of your blown fuse.

The electrical system, battery etc is for turning the starter, tilt motor and accessories, and engaging solenoids. The ignition system stands alone. The only weak link between the two systems is the rectifier.

The fuse is in the line running from the engine to the ignition switch and is also shared with the power tilt and trim. Check your harness carefully and you should find the short. The ignition switch itself is another good suspect.

The voltage output issue is caused by bad battery cables, a failing battery, or the wrong type of battery for a unregulated rectifier. Don't use a maintenance free car battery on that system.

 

[0rion]

Re: stator issue maybe??

The rectifier may be bad, but it is unlikely that it is the cause of your blown fuse.

The electrical system, battery etc is for turning the starter, tilt motor and accessories, and engaging solenoids. The ignition system stands alone. The only weak link between the two systems is the rectifier.

The fuse is in the line running from the engine to the ignition switch and is also shared with the power tilt and trim. Check your harness carefully and you should find the short. The ignition switch itself is another good suspect.

The voltage output issue is caused by bad battery cables, a failing battery, or the wrong type of battery for a unregulated rectifier. Don't use a maintenance free car battery on that system.

thanks to everyone for the replies. The cables are in excellent shape for the most part. I also just put a battery on it and used a marine starting battery. I'll chase those wires and check over the ignition switch and check for shorts. The 2 times it's done it were both while the boat was being started and not while it was running so it would make a little sense to start at that ignition switch and check it first.