1974 40 HP Question Charging problem revisted

[Howza]

1974 40hp Electric Start
I posted last week regarding my motor not charging back the batteries, I had a response of checking the rectifier and looking through a link which defined my exact motor. I have attached a couple pictures. 1). the overall side view, 2). which I think is the rectifier lower right behind fuel line cylinder?, and 3). my top view without flywheel. I was thinking that if the rectifier is not that expensive just to change it? Is this it? Is there anything else I should be looking for the motor runs fine could the charging coils be bad? How can I check the charge back to the battery, I assumme I must be running? I have a manual but it covers too many years and too many variations.

 

[Joe Reeves]

Re: 1974 40 HP Question Charging problem revisted

Yes, that is the rectifier. Due to cost (and to avoid being a parts replacer , test...... then replace only if necessary. Test as follows.

(Small Rectifier Test)
(J. Reeves)

Remove the rectifier wires from the terminal block. Using a ohm meter, connect the black lead of the ohm meter to the rectifier base (ground), then one by one, connect the red lead of the ohm meter to the yellow, yellow/gray, then the red wire (some rectifiers may also have a fourth yellow/blue wire. If so connect to that also). Now, reverse the ohm meter leads and check those same wires again. You should get a reading in one direction, and none at all in the other direction.

Now, connect the black lead of the ohm meter to the red wire. One by one, connect the red lead of the ohm meter to the yellow, yellow/gray, and if present, the yellow/blue wire. Then reverse the leads, checking the wires again. Once more, you should get a reading in one direction and none in the other.

Note that the reading obtained from the red rectifier wire will be lower then what is obtained from the other wires.

Any deviation from the "Reading", "No Reading" as above indicates a faulty rectifier. Note that a rectifier will not tolerate reverse polarity. Simply touching the battery with the cables in the reverse order or hooking up a battery charger backwards will blow the diodes in the rectifier assy immediately.

 

[dew2]

Re: 1974 40 HP Question Charging problem revisted

i JUST WENT BACK TO READ THE POST YOU MENTION oops cap lock.So what drain does your batt get just the starter? Or more?

 

[Howza]

Re: 1974 40 HP Question Charging problem revisted

I use a tricle solar charge to keep my battery level up, I will run for a while if I shut down to fish for a while, I have a tough time starting usually I need a Jump Pack to start again, The battery seems to be good, I have bought a new one just in case however this was a problem all last summer and am trying to get it solved now before the season.

 

[dew2]

Re: 1974 40 HP Question Charging problem revisted

Do you believe its a charging problem? Or do you just want to know the charging system is working?
By the sound of a tough time starting and needing a jump,I think I would start with that problem,starter,solenoid,dirty wiring bad contacts,Battery.Then I'd worry about a charge.
I use different motors and without any other elec. draw other than just a starter,A fully charged batt. lasts at least two weeks.Thats starting 2 -6 times a day 5 days a week.I just make sure I charge before I notice a power loss. bout every 2nd week seem to work for me.