25HP Merc not charging

[Smitty]

I have a '98 Merc 25HP electric start motor that isn't charging. Starts and runs fine, but just sits there at normal battery voltage when running.

Any ideas on what would cause this? I know on old snowmobiles there was a lighting coil that could cause it, is there something similar on these small outboards?

[REW]

What year is the motor?
Is it 2 or 4 cycle?

[Smitty]

1998 2-stroke

[REW]

It appears that this is your motor - or similar to it. I assume that it is a 2 cylinder?

https://public-mercurymarine.sysonli...=englangDB=eng

You essentially have two elements -
1. Rectifier - part # 62351A2 -- this is the same as the charging diode.

2. Charging coil or stator - part # 86704A2.

T his is the pickup coil that picks up energy from the spinning magnets on the flywheel to supply the charging voltage to the battery. After coming off of the charging coil, the voltage goes through the rectifier to be converted to DC for use as a charging voltage for your battery.

Rectifier sources:
https://www.google.com/webhp?sourcei...ifier&tbm=shop

Stator assembly - find #11 on the following:

http://www.marinepowerservice.com/Bo...pickyear/0.cfm

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As I said earlier, if you have a charging issue - the most frequent cause of failure is the charging diode, or rectifier.

The stator or charging coil could be the issue, but it seldom fails.

Good luck

[Smitty]

Thanks. A quick check with the meter indicates the rectifier is bad, new one on the way.