Stator?

Sugo

Petty Officer 2nd Class
Joined
Nov 11, 2008
Messages
160
I have a Mercury 150 EFI 2 stroke. The tach stopped working prompting me to look at the rectifiers. They were both shot. I replaced both rectifiers and ran the motor at an idle. My multimeter confirmed the voltage at the battery increased when the motor was running and the tach was working. I increased the RPMs and when it got around 1500 RPMs the tach stopped working, I shut the motor off and confirmed the two new rectifiers were burnt out. The 15 amp fuse on the red output from the stator was not blown. The motor runs well except the tach and the charging so one part of the stator must be good. The cost of a new stator is not cheep, so I was hopping to get another opinion before replacing the stator and two new rectifiers. Is there a voltage regulator built into the stator before the rectifiers and if so could that be the culprit? Something I am missing? And info is appreciated.
 

Faztbullet

Supreme Mariner
Joined
Mar 2, 2008
Messages
15,902
Did you replace with aftermarket rectifier/regulators or OEM? Was it the correct ones as they make a 16 and 40 amp rect/reg's??
 

Sugo

Petty Officer 2nd Class
Joined
Nov 11, 2008
Messages
160
They were aftermarket regulators not OEM. They looked identical and had no markings so I don’t know the amperage I don’t mind replacing them with proper OEM parts but don’t want to take a chance they would be damaged as quick as the last ones. Can I test the AC output from the stator via the yellow wires at higher rpm before installing them? If so how do I test? What should the AC voltage be? Would I use the two yellow wires to test? Or a ground?
 

Sugo

Petty Officer 2nd Class
Joined
Nov 11, 2008
Messages
160
Pulled to boat out of storage and want to address my rectifier issue. Am planning to purchase OEM rectifiers but need a tip on testing the stator charging circuit so I don’t damage expensive rectifiers. Two sets of yellow wires from the stator. Do I test the ac out put yellow to yellow or single yellow to ground? What ac voltage should I get. The yellow to yellow resistance reads about .8 ohoms for both sets of windings. Yellow to ground no continuity in either circuit.
Motor 1998 mercury EFI, 0G680506

thanks for any tips
 

Dukedog

Captain
Joined
Oct 6, 2009
Messages
3,420
send me an email addy and i will send ya an oem manual (in pdf) that will have your motor in it....
 

Sugo

Petty Officer 2nd Class
Joined
Nov 11, 2008
Messages
160
Issue solved. Thanks Dukedog for the manual. The specs from the manual confirmed my stator was good, and the wiring diagram helped me rule out anything that may damage my new rectifiers. Installed the new OEM rectifiers and it works perfectly. Lesson learned, after market parts can save money in certain applications but think twice befor buying aftermarket marine electrical parts, they will cost you more in the long run.
 

Dukedog

Captain
Joined
Oct 6, 2009
Messages
3,420
something ta consider with tha new reg/rectifiers if they have tha bullet connectors... best if you cut those off, solder and heat shrink tha joints.. tha bullet type are known for a heat problem........... jmo.
 

sam am I

Commander
Joined
Jun 26, 2013
Messages
2,169
Lesson learned, after market parts can save money in certain applications but think twice befor buying aftermarket marine electrical parts, they will cost you more in the long run.
Absolutely right, buyer beware comes to mind esp with some of the Chinese stuff out there, it's a crap shoot.

HOWEVER, not always, I bought a set of these over 5 years ago, and before I converted over to Shindengen's rec/reg's, these were still running 100% perfect(left in boat as good for spares).......I run three battery's with a charge management system and fish for hours at a time using 4 -10 amp electric down riggers for years now.

Typically, a little research and reviewing some buyer history's rating (4.5 stars rating for these) and you can save $100's over some very over priced products. Esp marine stuff.......
 
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