1981 140 Intermitent charging question

[ddbyrd3]

I did a search on previous post and found nothing that really described what I am seeing. The model # is J140TXCIM.<br /><br />On one accasion I take my boat out and the volt gauge will read 13 volts, I took the boat out yesterday and it read 12 volts. It never reads over 13 volts.<br /><br />I verified each time with my meter. I have a new stator, regulator, and rectifier on the motor, I have cleaned all grounds and everything else appears to be fine. I have never experienced a dead battery, and the volt gauge is a new teleflex vector.<br /><br />I was going to pull the flywheel to make sure the magnets were clean etc, any ideas what the problem may be??

 

[PRdiver]

Re: 1981 140 Intermitent charging question

I did a search on previous post and found nothing that really described what I am seeing. The model # is J140TXCIM.<br /><br />On one accasion I take my boat out and the volt gauge will read 13 volts, I took the boat out yesterday and it read 12 volts. It never reads over 13 volts.<br /><br />I verified each time with my meter. I have a new stator, regulator, and rectifier on the motor, I have cleaned all grounds and everything else appears to be fine. I have never experienced a dead battery, and the volt gauge is a new teleflex vector.<br /><br />I was going to pull the flywheel to make sure the magnets were clean etc, any ideas what the problem may be??

Hey DDBYRD3, I'm experiencing the same problem you had in a Mercury 150 hp, 1990. Can you please tell me what you did in that occasion to solve the intermitent charging problem? Thanks in advance, PRdiver

 

[emdsapmgr]

Re: 1981 140 Intermitent charging question

You may not have a problem. Normal battery voltage on the gauge should be around 12.6 volts give or take. When started, the volts may dip somewhat. After running the engine for 30 minutes, the volts may not go up much over 13 since you have a regulaltor on that engine. You might see 13.5. Volt gauges do vary somewhat in their readings. I doubt the flywheel magnets are a problem on your model.

 

[PRdiver]

Re: 1981 140 Intermitent charging question

You may not have a problem. Normal battery voltage on the gauge should be around 12.6 volts give or take. When started, the volts may dip somewhat. After running the engine for 30 minutes, the volts may not go up much over 13 since you have a regulaltor on that engine. You might see 13.5. Volt gauges do vary somewhat in their readings. I doubt the flywheel magnets are a problem on your model.

Thanks for your response; I replaced the cable from the regulator/rectifier to the starting solenoid where the charging voltage passes to the battery. Also I replaced the battery cables from the engine to the battery switch and to the batteries. After the cable replacement, the engine was charging OK. After 40 minutes of trailing to my house, I started the engine again and it was not charging. This Saturday I lunched the boat and went to a near beach without charging. During the return to the ramp the motor started to charge again. Around 13.5V at idle and 14.5V at 4500 RPMs. Because it was charging, on Sunday I went to fish, the motor charged for around 10 to 15 minutes and then it stop charging for the rest of the day. Around 6 hours with the engine running at different RPMs without charging.
Please let me know if this sounds familiar to you.
Thanks once again,
PRdiver

 

[emdsapmgr]

Re: 1981 140 Intermitent charging question

You mention checking various rpm's on the engine. From that I infer you have a tach setup on the engine. Also, you have not mentioned any issues with your tach operation while running your engine. In addition to charging the battery, the rectifier/regulator also sends a signal to drive the tach. Usually when the rectifier starts to act up (causing charging problems) the tach also acts up: reads erratically or not at all sometimes. The factory manual does have a test procedure for checking amp output from your engine's charging system. How new and in what condittion is the battery?

 

[PRdiver]

Re: 1981 140 Intermitent charging question

You mention checking various rpm's on the engine. From that I infer you have a tach setup on the engine. Also, you have not mentioned any issues with your tach operation while running your engine. In addition to charging the battery, the rectifier/regulator also sends a signal to drive the tach. Usually when the rectifier starts to act up (causing charging problems) the tach also acts up: reads erratically or not at all sometimes. The factory manual does have a test procedure for checking amp output from your engine's charging system. How new and in what condittion is the battery?

Hi EMDSAPMGR:
I really don't have problem with my tach at all. It is working good and read consistent. About My batteries, I have one Optima blue top that I bought around 5 years, but it still almost like new. The other is an Autocraft Boat/RV Deep Cycle it has near to a year. I tried the engine with the battery switch in bat 1, no charging; bat 2, no charging and both, no charging. That's why I can't identify if the bad part is the reg/rect or the stator. Do you know a test that I can make to identify the bad part?
Once again thank you for the support.

 

[Barnacle_Bill]

Re: 1981 140 Intermitent charging question

Test your rectifier. Instructions are in your manual. The rectifier can be bad and tach still work.

 

[PRdiver]

Re: 1981 140 Intermitent charging question

Test your rectifier. Instructions are in your manual. The rectifier can be bad and tach still work.

Thanks for your support. I replaced the regulator/rectifier and the problem is gone. Apparently it was a lazy rectifier problem.