1987 black max issue

88skeeter

Cadet
Joined
Jul 22, 2011
Messages
9
I have a 87 black max xr2 150 on my 88 skeeter 175. I just replaced the stator and rectifer. Took it out today to see if it was running better and charging. When I started it up and was running my fish finder only said 12.2 volts no matter rpm. It ran great and got on plane with no issue most of the day but after stopping for 30-45 min fires it up and it would not get on plane right away and would not go 2000 rpm. Took awhile and finaly got on plane and seem to run great. But when we went to load it it started hard and rough idle. Fells like it drop a couple cylinders. I am puzzled. And what should my voltage be when running with fully charged batteries.
 

j_martin

Admiral
Joined
Sep 22, 2006
Messages
7,474
Re: 1987 black max issue

I have a 87 black max xr2 150 on my 88 skeeter 175. I just replaced the stator and rectifer. Took it out today to see if it was running better and charging. When I started it up and was running my fish finder only said 12.2 volts no matter rpm. It ran great and got on plane with no issue most of the day but after stopping for 30-45 min fires it up and it would not get on plane right away and would not go 2000 rpm. Took awhile and finaly got on plane and seem to run great. But when we went to load it it started hard and rough idle. Fells like it drop a couple cylinders. I am puzzled. And what should my voltage be when running with fully charged batteries.

Should pull up to 14V or so. Maybe the voltage regulator on top of the engine is shorted. Discard it if it is. It's main purpose seems to be to catch fire. It's also possible that it took out the new stator or rectifier or both.

You might have another issue, such as a bad top main bearing that's taking out stators.
 

88skeeter

Cadet
Joined
Jul 22, 2011
Messages
9
Re: 1987 black max issue

The rectifer is the volatge regulator, that what I found. and how would you know if the bearing is bad. When I put the stator and rectifer in it did show it was charging but when got to the lake it said 12.2 volts. could the new rectifer be faulty or is the power packs faulty.
 

444

Senior Chief Petty Officer
Joined
Jul 16, 2010
Messages
704
Re: 1987 black max issue

A bad stator can cause you to eat a steady diet of rectifiers. When it starts to run bad on you, disconnect and tape up the two yellow wires going to the rectifier and retest the motor.
 

88skeeter

Cadet
Joined
Jul 22, 2011
Messages
9
Re: 1987 black max issue

The motor should run fine then after disconnecting? What would cause a new stator that is from cdi to go bad that quick?
 

j_martin

Admiral
Joined
Sep 22, 2006
Messages
7,474
Re: 1987 black max issue

The rectifer is the volatge regulator, that what I found. and how would you know if the bearing is bad. When I put the stator and rectifer in it did show it was charging but when got to the lake it said 12.2 volts. could the new rectifer be faulty or is the power packs faulty.

On an Xr2, there's a rectifier on the switchbox mounting plate, and a stator saturation regulator on the top of the block. They're pretty useless, like to catch fire, NLA, and are often removed.

The Mercury regulator/rectifier combo is a five or 6 wire unit that looks like this picture. It can be substituted.

Mounting.jpg



The mercury rectifiers are notoriously weak. A bad battery connection, or even a deeply discharged battery can take one out pretty quickly. I use one of these.

BridgeRectifier.jpg


If the top bearing is bad, there will be signs of contact between the stator and the magnets.

And yes, it's always possible to get new bad parts. Actually a very seldom occurrence from CDI, though.
 

88skeeter

Cadet
Joined
Jul 22, 2011
Messages
9
Re: 1987 black max issue

I checked for volatge regulator and there is not one. Its the rectifer/ regulator combo. I tested the rectifer today, I get continuity one way and not the other which means it should be good? Its hard to get it to act up when the motor is not loaded. The battery voltage out put of the rectifer is only 12 volts. I measured resistence of stator with specs from cdi and ohms are within specs. Ck voltage output per there test and it kinda jumps low to high voltage while reving the motor slowly at idle. All coils are firing. Started hard today. Can I meaure the output of the stator on the yellow wires for voltage to see if generating the proper amount. I ohm the yellow wires and got .008 ohms and is the shorted to ground. I have a call in to CDI for help but its looking like the stator is junk
 

j_martin

Admiral
Joined
Sep 22, 2006
Messages
7,474
Re: 1987 black max issue

I think you're right. Next time the flywheel is off, check for contact with the stator. Should not be any.
 

88skeeter

Cadet
Joined
Jul 22, 2011
Messages
9
Re: 1987 black max issue

I check for contact and did not see any. I guess just a bad part
 
Top