nyynuge

How much juice does a battery need to get the motor going?

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To clarify the title a little bit, does a battery need just enough power to get the flywheel going around, or does it need some force behind it to get it going. 

 

I have a 1980 something 2 stroke evinrude 70hp outboard btw.

 

I ask because the first time me and my buddy took out our "new" to use boat, we managed to run aground on a sandbar. The only way we figured out we had run aground was that when we went to leave the motor would start up but when we put it into gear it stalled, after doing this a few times, we accepted we had, had a massive mechanical failure, and decided to fish it out. After the first cast I discovered to my delight that we were only in a few inches of water and our prop was most likely suck hence why it stalled when going into gear.

 

After that we managed to drag the boat into a decent depth, only to discover that the motor now will not start at all, after a few minutes of trying to get it started we decide it's flooded and let it sit for about 15 or 20 minutes. Now at this point we no the battery is on our last legs and are getting another as this one only gets up to 11.6 volts but we bring a jump starter on board for this trip and figure it won't be a problem. After we let the motor air out a bit we try again for a few minutes and can here the battery starting to have trouble cranking it so we hook the jumpstarter up and keep trying. Then after a few more minutes all of the sudden it starts up, seemingly out of nowhere, and we drive back to the launch not wanting to tempt fate.

 

My question is: Could the battery being low been the problem will it not starting and the new one will fix it, or should we look into other problems like fuel delivery or the carb?

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More than likely yes it's just your battery , take old battery to auto zone and get it tested.Check your cables you might have fried them with all that cranking with low volts on the battery. Builds up alot of heat and will melt wires. That's the worst thing you can do is try and start on a basically dead battery. Could also have been bad battery connections.kill switch off maybe?

 

 

11.6 volts is not enough to start a motor.

 

Your volts should be 13.5v-14v. But under a load should be at least 500plus depending on battery specs.

Edited by 757saltwater

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More than likely yes it's just your battery , take old battery to auto zone and get it tested.Check your cables you might have fried them with all that cranking with low volts on the battery. Builds up alot of heat and will melt wires. That's the worst thing you can do is try and start on a basically dead battery. Could also have been bad battery connections.kill switch off maybe?

When I bought it there wasn't even terminals on it just the wire wrapped around the battery posts so the connections are all new and clean. I forgot a low voltage will draw more current, definitely gonna get it checked at autozone though. Thanks!

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Not exactly directly responsive to the thread, but with a small engine like that, you should also be prepared for a manual start if necessary.  There's probably a pull cord in a little bag up inside the cowling of the engine, that you can wrap around the flywheel and use to start the engine even when the battery is completely shot (sometimes you need to make an adjustment to the choke or throttle setting within the engine to make manual starting easier--see the engine manual for that).  Years ago, I had a 1983 Johnson 115 hp that I often started that way; your engine sounds like it's about the same vintage, and the smaller 70 hp should be that much easier to start with a cord.

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Not exactly directly responsive to the thread, but with a small engine like that, you should also be prepared for a manual start if necessary.  There's probably a pull cord in a little bag up inside the cowling of the engine, that you can wrap around the flywheel and use to start the engine even when the battery is completely shot (sometimes you need to make an adjustment to the choke or throttle setting within the engine to make manual starting easier--see the engine manual for that).  Years ago, I had a 1983 Johnson 115 hp that I often started that way; your engine sounds like it's about the same vintage, and the smaller 70 hp should be that much easier to start with a cord.

I'm afraid that cord appears to be long gone. It doesn't seem like it would be that hard though, I have turned it over by hand before. I'll see if I can throw a cord together.

 

My fear of that is that I'll either turn it the wrong way, or the cord would get caught in the fly wheel. 

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I'm afraid that cord appears to be long gone. It doesn't seem like it would be that hard though, I have turned it over by hand before. I'll see if I can throw a cord together.

 

My fear of that is that I'll either turn it the wrong way, or the cord would get caught in the fly wheel. 

There should be cutouts in the flywheel that show you where to attach the cord, and also indicate the right way to wind it.  If you look at the flywheel from above, you'll probably see three (I think) slanted cuts that go in matybe 3/4 of an inch and are rounded at the inner end.

 

What you do is get a length of parachute cord (or the equivalent in strength/size) long enough to wrap around the flywheel a couple of times.  Tie a knot in one end, and maybe drill a hole through abroomstick or length of 1" dowel about 4" long for a handle on the other.

 

When it comes time to use it, you slide the cord into one of those slots on the flywheel, with the knot poking out the top to hold it in place.  At that point, there is only one way that you can wrap it and keep it from pulling out of the flywheel when you wind,  At that point, assuming you have the choke/throttle set right, you just pull a few times until the engine hopefully starts.

 

Even with the battery working right, it's a nice backup to have, just in case. 

 

I've been running boats a long time, and if I've learned anything, it's that you always want a backup, for just about everything...

Edited by CWitek

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There should be cutouts in the flywheel that show you where to attach the cord, and also indicate the right way to wind it.  If you look at the flywheel from above, you'll probably see three (I think) slanted cuts that go in matybe 3/4 of an inch and are rounded at the inner end.

 

What you do is get a length of parachute cord (or the equivalent in strength/size) long enough to wrap around the flywheel a couple of times.  Tie a knot in one end, and maybe drill a hole through abroomstick or length of 1" dowel about 4" long for a handle on the other.

 

When it comes time to use it, you slide the cord into one of those slots on the flywheel, with the knot poking out the top to hold it in place.  At that point, there is only one way that you can wrap it and keep it from pulling out of the flywheel when you wind,  At that point, assuming you have the choke/throttle set right, you just pull a few times until the engine hopefully starts.

 

Even with the battery working right, it's a nice backup to have, just in case. 

 

I've been running boats a long time, and if I've learned anything, it's that you always want a backup, for just about everything...

Yes I know the cutouts you are talking about I'll definitely get a cord for this. Definitely beats my idea of having a big paddle as a backup.

 

For that to be effective though I really need to figure out what throttle/choke/primer settings this motor likes, it can be stubborn when cold.

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Yes I know the cutouts you are talking about I'll definitely get a cord for this. Definitely beats my idea of having a big paddle as a backup.

 

For that to be effective though I really need to figure out what throttle/choke/primer settings this motor likes, it can be stubborn when cold.

What I remember from my 115 was that there was a switch inside the engine that you moved for manual start.

 

Might be worth trying to find a manual for the engine, either something reproduced on the Internet or even if it was cheap enough, something on ebay, to let you know whether such a switch exists on your 70, and also for general information specific to the engine.

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Honestly I am a little disturbed that you couldn't tell your boat was aground, in a few inches of water no less...and continued to try and start it.  How does something like this happen?   Don't get me wrong I have run aground in a flats boat and in southern b bay in Nj...but I was in an area and water conditions where I always knew it was a distinct possibility...how does one end up aground and not feel how the boat is handling?

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Honestly I am a little disturbed that you couldn't tell your boat was aground, in a few inches of water no less...and continued to try and start it.  How does something like this happen?   Don't get me wrong I have run aground in a flats boat and in southern b bay in Nj...but I was in an area and water conditions where I always knew it was a distinct possibility...how does one end up aground and not feel how the boat is handling?

Yeah it shocked me too that's why we kept trying to start it.  As to how we didn't know we were aground, it's hard to say. What I think happened was that we drifted into the bar. I was piloting the boat at the time it happened, my buddy was and it was his first time ever piloting a boat so he didn't have any experience what it should feel like handling. But I think we stopped a few feet short of the sandbar and then drifted into it because there was a fairly strong current towards the bar. That would explain why we didn't feel a bump or anything. 

 

A few inches might have been a bit of an exaggerated a few inches too, it was maybe half a foot of water.

 

It mostly comes down to the fact it was the first time piloting that boat, his first time piloting any boat, and I have limited experience myself. 

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