alternator or not

[skruff33]

I have a Johnson 85esl70b motor .my question is when the motors running and I disconnect the battery cable is it normal for the engine to dye...or should it stay running....if any thanks again

 

[racerone]

That motor has a battery powered CD system.-------Motor will stop when you disconnect the battery !------------What is the reason for the question here ?

 

[skruff33]

Thank race was just making sure ..because it does die out when batt disconnected ....would you happen to no like what battery this engine would require it does have light system and few gages and was thinking adding a troll motor to the boat it is a 16 ft try hull

 

[Faztbullet]

You can damage the amplifier doing that!!!! $$$$$

 

[F_R]

Agreed, if the alternator were working, you would be in bad danger of blowing the expensive ignition amplifier. Disconnecting the battery when running will also blow the rectifier, which is why your alternator isn't working. Is it ok to shout here? DON'T do that!!!!

 

[skruff33]

I was wondering .if I had a alternator or how does my motor stay running but race explained it the best it don't have a alt and is ran off the battery .....correct

 

[skruff33]

Or does my engine charge the battery sum how..

 

[racerone]

??????----------I believe you are totally confused by the workings of your motor.------What is the model # of it ?---------Big outboards have had flywheel alternators for many years since the early 1960's !!!

 

[F_R]

Scruff, your motor does run off the battery. But it also does have an alternator which keeps the battery charged. Now, according to your original way of thinking, when you disconnected the battery, the motor should have kept running, now being fed by the alternator. But...as we have already warned you, doing that puts it in serious danger of destroying some costly parts, so don't do it. As you proceed with this project, you now will have to test the alternator rectifier to see if you blew it. And I predict you did, or possibly it was already blown. If the motor runs again (with the battery connected), the ignition amplifier survived and you can give some thanks for that.

 

[racerone]

In another post you ask about a battery for a 1973 model 85 hp.---------Do you have 2 motors ?

 

[skruff33]

OK so engine does still start and run normal so all parts are fine...just don't no how to tell if the alternator or charging system is functioning b properly ....1973 85 hp Johnson ..model 85esl73b..any test or sum way to no if it is working ...it did dye out when cable was removed ..understand don't do that...but should it have stayed running ...bat disco. .or no ...is it normal..

 

[racerone]

If you have a 1973 model 85 HP then the ignition system runs off the magneto and not from a 12 volt battery.---Test battery voltage with motor stopped and test battery voltage at a fast idle. --Report your values.-That motor would keep running with the battery disconnected.--Not a good idea to do that

 

[emdsapmgr]

According to the model number Scruff provided at the top of this thread-the engine is a 1970 85 hp engine.

 

[Faztbullet]

...but should it have stayed running ...bat disco. .or no ...is it normal..

The answer for your model is no and is normal. Your engine has a 6 amp stator and will charge the battery while running if the stator and rectifier is good. You can test buy measuring the battery voltage before starting say 12.3 volts and when started and running raise rpm up to about 2000rpm and you should see voltage rise to about 12.7-12.9volts. It only puts out 6 amps at wide open...

 

[racerone]

I have already asked the poster to tell if he has one motor or two as they are not all the same.---He asks questions on 2 different motors.

 

[skruff33]

1 motor

 

[racerone]

OK---So which of the 2 are you working on 1970 ----85 or the 1973 ------85.------You have asked questions on both !!!

 

[skruff33]

I'm sorry I'm working on the motor it's a Johnson 85hp 1970 model # is 85esl70b....sorry for the confusion the boat it's on is a 1973 ...