150 hp voltage regulator

dannvandenbroek

Recruit
Joined
Jan 28, 2008
Messages
2
Hi there,

I've got a 150 hp mercury with s/n 6043247 . It is a engine with just a rectifier and without a regulator. It has a 2 yellow wire stator.
Now I found out that the engines with serial # up to 0A904646 got a 2 wire voltage regulator with p/n 88825A7.
Is it possible to introduce this onto my engine? Will it harm the stator? I think is won't since i suspect that this voltage regulator isn't affecting/regulating the stators electric field since it only got 2 wires. I think it is just a "old fashioned" regulating resistor voltage regulator.
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
27,036
Re: 150 hp voltage regulator

You could likely retrofit your motor with a 20A or 40A V/R. The real question is why do you want to do this? Normally the charging system on those old motors is only 5-6A, so the battery can absorbe the load easily.
 

j_martin

Admiral
Joined
Sep 22, 2006
Messages
7,474
Re: 150 hp voltage regulator

You have either a 9 or a 16 amp system. The old 2 wire regulator sitting on top of the block sometimes works, but usually just burns itself out of the circuit. Ultimately the battery characteristics hold the voltage down, and you "use" about a battery a year if you do much boating.

Best fix for now is to retrofit one of the 20 amp regulators usually used in a 40 amp dual coil system and some of the newer 16 amp systems. It would replace both the rectifier and the regulator. It will work fine, and truly regulate the output. Takes some cut and crimp work to put in, and you'd have to probably make a mounting plate for it, but probably worth it.

hope it helps
John
 

dannvandenbroek

Recruit
Joined
Jan 28, 2008
Messages
2
Re: 150 hp voltage regulator

Thanx for the feedback.

By change ,you got me a partnumber of that kind of regulator/rectifier. I allready found p/n 88825A7 as one of them (true?).
But the charasteristics of a battery will limit the current and not the voltage. So won't the battery be harmed by overvoltage while running without a regulator?
 

j_martin

Admiral
Joined
Sep 22, 2006
Messages
7,474
Re: 150 hp voltage regulator

Thanx for the feedback.

By change ,you got me a partnumber of that kind of regulator/rectifier. I allready found p/n 88825A7 as one of them (true?).
But the charasteristics of a battery will limit the current and not the voltage. So won't the battery be harmed by overvoltage while running without a regulator?

No, the battery acts as a voltage regulator. A charged battery in good condition will take almost no current at 13.5 volts, and take it all at 15 volts. It makes hydrogen and oxygen out of the water with the extra power.

This process is harmful to the battery, so it is, IMHO, poor design.

I don't know the part numbers of the regulators. There are 2 versions by mercury. One has a clear potting and 5 wires (internal ground) and the other has black potting and 6 wires. (external ground). The wires are 2 yellow go to the stator, 2 red go to the battery, 1 grey to the tach, and an optional black ground wire. The external ground one is better. Either one will work for you.

CDI makes a replacement one that is better yet, and will work.

Below are pictures of the merc 6 wire and the CDI units

hope it helps
John
 

Attachments

  • merc_reg_top.jpg
    merc_reg_top.jpg
    19.9 KB · Views: 0
  • Voltage Reg.jpg
    Voltage Reg.jpg
    23.5 KB · Views: 0
Top