# Importance of a fully charged battery



## AnglerC (Sep 12, 2016)

An oversight on my part left me on a like with a 40 horse OB Evenrude and a battery so low it triggered the low battery alert on my fishfinder. 

This was the first time I had had it back on the lake since I had the carbs done in late June. (long story). 

Needless to say the motor was cutting out or bucking at low rpm and died frequently. It did not do it at higher rpm. Before the carbs were done it did the same thing but also did it at higher rpm. 

So my question is. Was it giving me fits due to a low battery or is it not repaired after the carbs were done?


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## lovedr79 (Sep 12, 2016)

i would try it with a full battery before i took the carbs back off. i have seen some ATV's run like crap with a dead battery. one inparticular would idle all day long. tuoch the gas it would die. for giggles i got out jumper cables and a car battery. ran like a champ.


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## jbird68 (Sep 12, 2016)

Do you need a battery once the motor has been started? Why would it affect the way the motor runs?

Sincerely, 

jbird68


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## Texas Prowler (Sep 12, 2016)

A bad battery would do that to any engine. Try having the battery load tested. That will tell you what you need to know about it.

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## Pappy (Sep 12, 2016)

NO, a bad battery will NOT do that to any engine. 
Your Evinrude 40hp needs NO battery to run at all. You can rope start it and run. 
This engine as well as most if not all carbureted engines use a mag CD style ignition that generates its own power to run once the flywheel is turning. 

Now, on to your issue. You have, on that engine, (3) seperate circuits on your carburetors. These circuits control idle, midrange, and high speed fueling. 
Your issue suggests your idle circuits are either plugged up again or improperly adjusted or the Sync and link needs to be done.


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## Texas Prowler (Sep 12, 2016)

Not trying to argue but read the first sentence... Either it's not getting a charge or can't be changed.

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## Pappy (Sep 12, 2016)

Now we are getting off track. He indicated he started the engine with less than a fully charged battery. 
The engine ran. 
This same engine is made in a rope start, tiller operated configuration. No battery required on that engine and the same ignition system. 

The charging system on that engine is totally separate from the ignition system. The charging system has zero to do with ignition.
I gave you the explanation on how the system works in a short version. Read it again. Needs no battery to run.


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## lovedr79 (Sep 13, 2016)

if there is a completely DEAD cell or two in the battery this would cause the "loop" to be incomplete. some ignition systems have to have a complete loop to run causing havock on the ignition.


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## overboard (Sep 13, 2016)

I would have to agree with Pappy! Just for piece of mind put a fully charged battery on it, I doubt if that will solve the problem and you will be looking at the carbs. 
Some electric start motors come with a rope and can be started if the batter is stone dead, those motors can be started and will run just fine without a battery. My 100hp Mariner has a starter rope in the cowl from the factory, I hope I never need to use it! :lol: 
Just a thought, even though the carbs were done they could have been recontaminated.
Just saw the above post, I don't know what a dead/shorted cell would do, but would be worth checking the battery out first and then go from there.


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## Pappy (Sep 13, 2016)

lovedr79 said:


> if there is a completely DEAD cell or two in the battery this would cause the "loop" to be incomplete. some ignition systems have to have a complete loop to run causing havock on the ignition.



Give us an example of that in the vintage the OP is running. Looking forward to your reply.

Hint. On an Evinrude that is normally started by a battery just remove the battery altogether and start the engine with the rope.


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## lovedr79 (Sep 13, 2016)

I can tell you for a fact that a 1971 Honda SL70 with battery and kick start will not run without a battery. I do not know all of the specifics of the OP's OB. More importantly is what has the OP done since they started this thread.


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## DaleH (Sep 13, 2016)

overboard said:


> Some electric start motors come with a rope and can be started if the batter is stone dead, those motors can be started and will run just fine without a battery.


You meant to add, of course ... provided that the key switch was still turned to 'ON' ...


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## Texas Prowler (Sep 13, 2016)

Pappy since I've had my 73 50hp Johnson I've started it with a known bad battery. It has a bad cell. I've had it load tested. Just because it started doesn't mean it isn't bad. Again not arguing just pointing out facts. Just thinking outside of the box here as there are other possibilities. The op wouldn't even have to buy an extra battery to test this theory. 

Sent from my LGLS991 using Tapatalk


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## Pappy (Sep 13, 2016)

Texas Prowler said:


> Pappy since I've had my 73 50hp Johnson I've started it with a known bad battery. It has a bad cell. I've had it load tested. Just because it started doesn't mean it isn't bad. Again not arguing just pointing out facts. Just thinking outside of the box here as there are other possibilities. The op wouldn't even have to buy an extra battery to test this theory.
> 
> Sent from my LGLS991 using Tapatalk



Okay lets go back to basics here. 
Go back and read the OPs post again. The issue was that the engine ran rough at low RPM and the OP wondered if the low battery was the culprit.


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## turbotodd (Sep 13, 2016)

lovedr79 said:


> i would try it with a full battery before i took the carbs back off. i have seen some ATV's run like crap with a dead battery. one inparticular would idle all day long. tuoch the gas it would die. for giggles i got out jumper cables and a car battery. ran like a champ.




yep. Kawasaki Prairie 300 and 400, Bayou 300 and 400, some Honda ATV's, Kawi Prairie 360, 650, 700, many kawi motorcycles (750 vulcan I'm working with currently, requires a GOOD battery to run properly), etc etc. I haven't heard of any outboards requiring a battery to run properly. Doesn't mean that they will ALL run right without a good battery, just means I've not heard of it (yet). Maybe the bigger motors. EFI anything for the most part, requires a battery-with the exception of a very few machines....Merc 25hp EFI is one of them, and now the Suzuki outboards (both are batteryless EFI). Lot of the motocross bikes 250cc and 450cc are EFI and no battery but the technology behind this is still a little behind, in that you can't slowly kick it over and expect it to start...it takes a swift kick of the start lever (or a swift pull of the starter rope).

Those are the ones I know of off the top of my head based on my personal experience with them. 

Most everything is a CDI style ignition, especially the newer (1980 and newer) japanese stuff. There are two main types of CDI systems. AC-cdi and DC-cdi. AC will have a coil on the stator assembly that powers the CDI (aka source coil). DC CDI systems require 12v to run properly, usually in the form of a good battery. 

Most older carbureted outboards don't NEED a battery to run correctly, but if the system is electric start and has a charging system, it's hard on the regulator/rectifier to continue to use the motor without a battery. 

In the original poster's case I doubt the low battery had anything to do with the running problem, but I'm not an Evinrude guru either. Could be a hundred things causing the poster's problems. Timing, carb(s), linkages, etc.


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## Pappy (Sep 13, 2016)

lovedr79 said:


> I can tell you for a fact that a 1971 Honda SL70 with battery and kick start will not run without a battery. I do not know all of the specifics of the OP's OB. More importantly is what has the OP done since they started this thread.



Good example, but we are talking about outboards here of the vintage the OP is having issues with. Are you a Honda motorcycle fan as well? My better half and I both ride Honda Valkyrie motorcycles. She grew up on nothing but Honda bikes.


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## overboard (Sep 13, 2016)

DaleH said:


> overboard said:
> 
> 
> > Some electric start motors come with a rope and can be started if the batter is stone dead, those motors can be started and will run just fine without a battery.
> ...



You have a good point there!
I remember one time we were pushing a guys car around to try to catch it in gear to start it, it wouldn't start until someone asked him if he had the ignition key turned to on, he forgot that part! #-o


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## JMichael (Sep 14, 2016)

Pappy said:


> Now we are getting off track. He indicated he started the engine with less than a fully charged battery.
> The engine ran.
> This same engine is made in a rope start, tiller operated configuration. No battery required on that engine and the same ignition system.
> 
> ...


What's that old saying about leading a horse to water? :lol:


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## lovedr79 (Sep 14, 2016)

i am a fan of Honda. that was my first dirtbike. learned alot of wrenching skills on that old bike. l like honda ATV's, KTM dirtbikes and Harley street bikes. i have had several hondas in various forms though. my current street bike is a harley.


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## JMichael (Sep 14, 2016)

lovedr79 said:


> i am a fan of Honda. that was my first dirtbike. learned alot of wrenching skills on that old bike. l like honda ATV's, KTM dirtbikes and Harley street bikes. i have had several hondas in various forms though. my current street bike is a harley.


My first bike was a 1971 Honda CB175. I rode my current bike off the showroom floor one year after I got my discharge (1981). It runs as good today as it did then. No one else has put a wrench to it other than me since the warranty expired. I even gave it it's current paint job myself, but I paid someone else to powder coat the frame and some other misc parts while I had it disassembled.


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## lovedr79 (Sep 14, 2016)

here is my Harley. now that we have gotten WAY off track. LOL!


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## JMichael (Sep 14, 2016)

Yea, it's off topic but it keeps his thread active while we wait to hear back from him. LoL Nice looking bike. Sportster if I'm not mistaken. When I bought my 81, my girlfriend (and future ex wife) had a 1980 "bowling pin" sportster as we called it. I think it was the last year that AMF owned and built harleys.


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## Pappy (Sep 14, 2016)

Jmichael - what model is that in the photo? 

My turn......

Lesa on her Vstar 1100 Custom. Nice and comfy ride but low horsepower and buzzed the handlebars above 70-75mph.
Her 1994 Honda Magna V4 would blow it away and not break a sweat doing it. Would also keep up with the Valkyrie pretty well. 





Lesa on her Blue and Cream Valkyrie.





My red and black Valkyrie


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## lovedr79 (Sep 15, 2016)

JMichael said:


> Yea, it's off topic but it keeps his thread active while we wait to hear back from him. LoL Nice looking bike. Sportster if I'm not mistaken. When I bought my 81, my girlfriend (and future ex wife) had a 1980 "bowling pin" sportster as we called it. I think it was the last year that AMF owned and built harleys.



the good ole AMF bikes. yes it is a 2007 sporty. i love it. all i need.


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## nowgrn4 (Sep 15, 2016)

Hey Pappy, any truth to this? Never try and start a FITCH or E-Tech outboard with a low battery. It can damage the ECU.

???


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## JMichael (Sep 15, 2016)

Pappy, that is my 1981 KZ 1000 LTD (K1). I've installed some Kuryakyn grips and different mirrors since that picture was taken, but other than that, it still looks the same. I like the styling of those Valkyrie. Looks like a nice bike for taking long trips.


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## lovedr79 (Sep 16, 2016)

nowgrn4 said:


> Hey Pappy, any truth to this? Never try and start a FITCH or E-Tech outboard with a low battery. It can damage the ECU.
> 
> ???



never heard that before. is it in the owners manual somewhere?


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## Shaugh (Sep 16, 2016)

You would need to know what year the motor is and research whether it has electronic fuel injection or other computer controlled functions. If it's just a carburetor/ magneto motor the battery condition will not affect the running performance. A dead cell in the battery will likewise not affect it. As long as the battery is grounded and can accept the current from the charging circuit, running the motor will not damage it (the fact that the motor was started proves it had a complete circuit).

My guess is you have carb problems unless this is a later model motor with a DC stator type electronic ignition. In that case your problem is that your charging circuit is likely malfunctioning. Once the engine is running the stator should generate more than enough energy to power the ignition unless it is not working correctly.


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## nowgrn4 (Sep 16, 2016)

lovedr79 said:


> nowgrn4 said:
> 
> 
> > Hey Pappy, any truth to this? Never try and start a FITCH or E-Tech outboard with a low battery. It can damage the ECU.
> ...





I had a IMHO very knowledgeable older Gentleman that works in management at a local BRP dealership tell me this.


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## lovedr79 (Sep 17, 2016)

That sounds a little odd. So I guess they sell alot of ecu's?


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## JL8Jeff (Sep 17, 2016)

One problem I ran into with a 1992 Boston Whaler Rage with the Yamaha 650 motor was the weak battery cooked the points in the solenoid so trying to start it was a crapshoot. It took me a while to diagnose what was wrong. Nothing worse then turning the key and getting the dreaded click, click. I'm not sure if a weak battery could affect the electrical while running, but if the key is in the running position, I would think it's trying to power all the accessories and run the engine would could possibly lead to a power shortage somewhere.


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## Sinkingfast (Sep 17, 2016)

lovedr79 said:


> I can tell you for a fact that a 1971 Honda SL70 with battery and kick start will not run without a battery. I do not know all of the specifics of the OP's OB. More importantly is what has the OP done since they started this thread.




That SL has a battery excited field and the ignition runs off this type of charging system. Once its started it will run with no battery. 

Some charging systems have a voltage regulator in parallel with the battery. Anything over 13.4dc or something gets dumped to ground. If no battery the regulator dumps all to ground.


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## AnglerC (Sep 19, 2016)

OMG you guys I am so sorry I fell off the face of the freaking earth. Long story and maybe we talk about it some other time.

Back to the boat. I put my charger on the battery and it's this digital kind of charger from Craftman. It charged the rest of that day, all night and most of the next day until I took the charger off the terminals and charged a different battery to see if my charger was bad. It charged the second battery so I put it back on my first battery. Now... It charged the rest of the day again, over night again and that morning it said it was at 90% charge and I unplugged it. I have not had a chance to get it back on the lake to see if it's running correctly. 

The guy I had do the carbs says he tested it under load and it ran fine. I could try just running it on the ear muffs and see if it does it. 

I'm so sorry it has taken me this long to get back to you guys... Great bikes though. LOL...


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