Engine cranks slow, but batteries are charged

[DLT]

If you believe the hype, Evinrude says something to the effect of:

The ETEC's alternator produces enough electricity to start and run well within the first revolution.

I wanna say it supposed to be something like the first 1/4 revolution...

Of course, I doubt that is while conencted to a dead battery...


Although, the ETEC is supposed to run without a battery at all.


But, I'm not looking forward to that first time I have to pull the rope on a 2-stroke... I remember nearly getting my leg broke, several times, trying to kick start a dirt bike...

[Chip Hindes]

ANyone have an alternator vs rpm production curve??

I've often thought that would be a handy item to have. Probably anyone with one of those fancy Link electrical system doodads, or even a simple ammeter could build a simple one.

It's kind of off the subject of this thread, but I've often thought the most limiting factor in the discussion of electrical use is the rather anemic output of the alternators. It would be way easier to forget the overpriced solar and LED lights and just fit a whopping big alternator; say 60-80 amps, which could charge the battery up in fifteen minutes or so instead of an hour or more after a night's use.

I understand and appreciate the desire of some to stay green with reduced consumption and passive generation, but rerouting a small fraction of our ample motor horsepower to turning a high output alternator rather than the prop would seem to me a pretty efficient use of resources. It also seems like you ought to be able to buy a larger alternator for little more than the price of a single LED anchor light, and way less than an equivalent output solar panel.

But...

I haven't looked into this other than a quick Google search which yielded nothing; however, it appears that higher output alternators for outboards simply don't exist. You get what comes with the motor, period. I suppose the problem is that most 26 foot boats that have the power consuming goodies of many of our boats also have honking big motors with way more alternator output, while the 10-15A net of our motors is plenty for most boats powered by them. Too small a market for a large alternator on a medium sized outboard to justify making one.

[DLT]

Scroll down this thread for a picture of an automotive alternator mountd atop an outboard...

[Chip Hindes]

I guess that's one solution. Of course the "preferred embodiment" would be something that was a plug in replacement for the standard alternator.

That thing looks like it might last about 1-2 minutes in a salt water environment

[DLT]

"preferred embodiment"

Now that's not a term I hear except in the Patent arena...

Who knew? Chip is a certified inventor!!!


Patent #1

Patent #2

[Don T]

Hello:
The ignition power & trigger coils can develop enough juice to fire. It takes one revolution for the computer to know what to do. All you need is more than 10 volts (possibly 9) to keep the computer up and fuel pump working. However, if the battery is real dead/bad when the motor starts the voltage may spike and the it will be toast. Theoretically, if the batt has 9 or 10 volts then it will accept current from the charging system without spiking. As long as you can get the injectors to fire (25ms @ 1A ea), you are good to go. It would be easy to check the current draw of the systrem start up (sans starter). My guess would be 5 amp spike with 500 ma KOEO. Probably pulls 3~4 amps when running. Even without the 50~80 amps to run the starter it is a substantial load for a dead batt.

[Chip Hindes]

Sorry, I had just finished reading through a bunch of patents and that phrase was stuck in my mind.

It is rather catchy though, don't you think?

[DLT]

I use it all the time...

[Bob Zoobricke]

I had the same problem. The cause was vapor lock cause by the eigine being to hot, but not hot enought to overheat. Change the thermostat.
That should correct your problem.

[nemo]

Wow, I was away from the board a couple days and found many more posts - Thanks my Friends, let me respond to some of the comments..

DonT: I'll be carrying my VOM with me in future so if this happens again I can try and pinpoint where the voltage drop is occuring (I'm an electrical engineer so understand the principles you're trying to get across.) At this point it's starting as snappy as ever so I doubt I'll find anything bad.

Chip: Your story makes me want to try and start our motor with a rope just to see how easy it is - before I ever need to count on it. Probably a good idea for all of us.

DLT: I've had many 2-stroke dirt bikes (you can see them at
http://www.brownz.com/Bike%20Gallery.htm if you really care) and know what you mean about the kickback - although that's only a problem with a solid kick-starter. A flimsy rope won't transmit any energy back to you (like pushing a wet noodle).

Daves_knot_here: Our Raymarine ds400 is wired into the house battery, as that is the one that I figured would have the most fluctuation. I hope to always keep the engine battery fully charged. I knew the ds400 has the feature to display voltage, but since it can't display voltage on both engine and house batteries I installed a separate voltage meter with a manual switch so I can look at voltage on each battery independently.

FrankC: I like the idea of bringing along a charged jump-start battery. I've been wanting one of those anyway for other purposes - this kinda justifies picking one up.

Jeff Stagg: I think I read you right the first time, about when the shifter is not fully engaged into neutral. I got bit by that once, for a few minutes, when it was still in gear and turning the key did not start the engine. You got me thinking that maybe there's a spot where the shifter is just partially engaged into neutral so there's a high-Resistance connection to starter.. not sure there's prior art on that, but it's just another embodiment of one of our plurality of theories.

Bob Z: vaporlock? Well I can see that causing an engine to stall or not start, but the starter would still be cranking good and strong in that case. This was a problem of the starter barely turning over, as if I had a near dead battery. Thanks for chiming in with your idea though - thanks everyone for all the ideas.

[nemo]

Whoops - regarding my response to DLT's comment regarding potential kickback pull-starting the engine, my brain was not engaged last night when I made the comment about pushing on a rope - it was incorrect. My apologies.

"Kickback" implies a reversal of engine direction (could be for just a moment or longer.. actually had my Husky 430 2-stroke running backward a time or two after I gave it a very weak kick to start it), so it could theoretically yank the rope back. Not a happy thought.. Anyway, sorry for any confusion.