Chaparralbob
Seaman
- Joined
- Jun 30, 2009
- Messages
- 64
I have been restoring a 1990 Lowe pontoon boat with a 1990 Evinrude 70 HP.
The battery is not charging. I have read many posts on this, but haven't come across the particular set of test results I got.
I tested the bridge rectifier, and got the correct readings for all 4 diodes.
I measured the AC voltage into the rectifier with the engine running (across the two yellow leads), and it was only about 9 volts (with the rectifier output connected to the battery). The battery is fine, by the way, and has started the motor right up about a dozen times. I charged it with a regular battery charger prior to this testing.
I measured the voltage across the disconnected stator with the engine running, and got about 40 volts (AC).
I then measured from one side of the stator winding to ground, and also got 40 volts (AC).
When I measured the other side of the stator against ground, I only got about 3 volts (AC).
With an ohmmeter, I measured the disconnected stator coil, and it shows open (no continuity). When I measure from one side to ground, I get about 1.7 ohms. I checked the ohmmeter by shorting the test leads, and it reads zero, so this is a fairly accurate value. When I measure from the other side of the stator coil to ground, it shows open.
For one thing, there shouldn't be a connection to ground. Getting a voltage across the 2 unconnected stator wires when I can't read continuity is also troubling. May be it is just the high input impedance of the multimeter I'm using. It is decent quality - about $80 if I remember correctly. Obviously, something is not right.
Question - are the coils in the stator wired in series? If so, it would seem that one of the coils is shorted to ground somewhere, and another (or the same one) is open to the bad lead of the stator.
Also, the tachometer seems to be indicating a much higher RPM than what it should. I think it was about 3000RPM with the engine idling. I'm guessing that the motor is actually idling at about 1000RPM. I have it set for "6", which I believe is correct for the Evinrude 12-pole stator.
It seems as though I will need to replace the stator!
I haven't taken the flywheel off yet. Does anyone know the thread size of the bolts in the flywheel that are used with the puller? I looked at the OMC $90 puller, and it just looks like something I can get elsewhere for $20, if I know what bolts I need; grade 8 as I understand.
This boat/engine came as part of a piece of property I bought at Lake Gaston, NC. Based on the money I have spent so far, about $3000, it certainly wasn't free! However, if I can get this, and a fuel starvation (I think) problem solved, the pontoon boat will be ready for the lake!
Thanks for any help with this!
Chaparralbob
The battery is not charging. I have read many posts on this, but haven't come across the particular set of test results I got.
I tested the bridge rectifier, and got the correct readings for all 4 diodes.
I measured the AC voltage into the rectifier with the engine running (across the two yellow leads), and it was only about 9 volts (with the rectifier output connected to the battery). The battery is fine, by the way, and has started the motor right up about a dozen times. I charged it with a regular battery charger prior to this testing.
I measured the voltage across the disconnected stator with the engine running, and got about 40 volts (AC).
I then measured from one side of the stator winding to ground, and also got 40 volts (AC).
When I measured the other side of the stator against ground, I only got about 3 volts (AC).
With an ohmmeter, I measured the disconnected stator coil, and it shows open (no continuity). When I measure from one side to ground, I get about 1.7 ohms. I checked the ohmmeter by shorting the test leads, and it reads zero, so this is a fairly accurate value. When I measure from the other side of the stator coil to ground, it shows open.
For one thing, there shouldn't be a connection to ground. Getting a voltage across the 2 unconnected stator wires when I can't read continuity is also troubling. May be it is just the high input impedance of the multimeter I'm using. It is decent quality - about $80 if I remember correctly. Obviously, something is not right.
Question - are the coils in the stator wired in series? If so, it would seem that one of the coils is shorted to ground somewhere, and another (or the same one) is open to the bad lead of the stator.
Also, the tachometer seems to be indicating a much higher RPM than what it should. I think it was about 3000RPM with the engine idling. I'm guessing that the motor is actually idling at about 1000RPM. I have it set for "6", which I believe is correct for the Evinrude 12-pole stator.
It seems as though I will need to replace the stator!
I haven't taken the flywheel off yet. Does anyone know the thread size of the bolts in the flywheel that are used with the puller? I looked at the OMC $90 puller, and it just looks like something I can get elsewhere for $20, if I know what bolts I need; grade 8 as I understand.
This boat/engine came as part of a piece of property I bought at Lake Gaston, NC. Based on the money I have spent so far, about $3000, it certainly wasn't free! However, if I can get this, and a fuel starvation (I think) problem solved, the pontoon boat will be ready for the lake!
Thanks for any help with this!
Chaparralbob
