Topic: Will 550 run on dead battery?

[ajinreno]

I must apologize in advance. I'm a newbie to Honda's. I've always had Vespas and Lambrettas that I have worked on, but no 4 strokes, let alone something with 4 frickin carburators!!! So I'm sure I will ask lots of dumb questions...like this one.
 My bike sat for quite a few weeks while i waited for a new petcock and orings for my float bowls. The battery died. I've had plenty of vespas that I ran with dead batteries, so hopped on kick started it and road it to work...didn't get a chance to charge it last night, so did the same today. Except while cruising along at about 50 it died on me (it seemed to run on 2 cylinders for about 20 seconds before dying, but i could be wrong.) I was able to fix it by standing next to it and staring at it for 10 minutes. Then it started up and rode the rest of the way to work.
Is this because of the dead battery? I read in some older threads that it can cause numerous problems, but nothing was specified. My rudimentary knoweldge of motors told me that it doesn't need a battery to make a spark...just to start and run lights. Am I wrong?

[TwoTired]

The coils need electricity to function.
The alternator on the SOHC4 needs power to make a magnetic field for power generation.
With dead battery, no power for coils = no spark.
With no power to the alternator, spinning the alternator makes no power.

SOHC4 needs a good battery to run.

Cheers,

[ajinreno]

Thanks for the clear and concise answer... Hopefully I will make it home to my charger!...and hopefully it will hold a charge.

[number13]

As Twotired stated, none of these SOHC bikes will
run with a dead battery. Your problem sounds a
lot more like fuel starvation. Remove and clean
your petcock and any in line fule filters.

[CrisPDuk]

The coils need electricity to function.
The alternator on the SOHC4 needs power to make a magnetic field for power generation.
With dead battery, no power for coils = no spark.
With no power to the alternator, spinning the alternator makes no power.

SOHC4 needs a good battery to run.

Cheers,

Well you learn something new everyday.

I was always under the impression that once started, they would run quite happily with no battery at all

I know cars will function this way

[hapsh]

It wont run on a dead battery, however, they usually run the worst below 2k rpm where the charging system is hardly charging.  Even with a very low battery the voltage regulator will supply enough voltage to the alternator to get your charging system generating enough to run ok above 2500 rpm.  If the battery is so dead that it can't supply the alternator enough voltage to start generating, well, the bike wont start at all.  I ran mine with a very old bad battery, and it ran OK as long as I kept the rpm's up a bit.  But when it is running on a bad battery it usually runs poor at low rpm on all cylinders,  not just two.  Also, letting a bike sit with a bad battery wont usually be a temporary fix.  What you are describing is fuel starvation.  Sounds like you might have a slight clog in your petcock or tank vent.  On my '76 550 it has two fuel lines.  When you run out of gas it stops supplying gas to cylinders 3-4 first because the fuel fitting for cylinders 1-2 are first in line to get the remaining fuel.  Use clear fuel lines so you can make sure fuel is flowing.

[edbikerii]

Do you have an electronic ignition?

My experience with electronic ignition is that they don't work at all if the voltage is too low.  So, it is basically impossible to start the bike, even with the kickstarter, if the battery is too low.  I believe points are much more forgiving here.  I may be completely wrong about points because I only owned my bike for a few months before I switched over to a Dyna-S ignition.

[TwoTired]

Car alternators generally spin fast enough, even at idle, to make more power than is used by the vehicle.  The SOHC4 does not.

A standard SOHC4, with lighting on, draws about 130 watts (assumes 12.8 V present in system).  Consumption falls with lowered voltage, per ohms law. (Current equals Voltage divided by circuit resistance)
The stock alternator makes about 30-50W at idle depending on model and a battery holding up the system voltage.  Higher RPM can overcome the bike power loading and self sustain the alternators generation ability.

A depleting battery lowers the system voltage. (And load consumption, making calculations constantly changing)

At some point there isn't enough voltage to produce reliable spark.  That's when far more sound comes from the operator than the engine.

Cheers,

P.S.  It is not wise to run alternators without a battery connected.  The battery damps charging and electrical system voltage spikes, which may exceed withstand level of the rectifier diodes.

[Gordon]

Thanks for the clear and concise answer... Hopefully I will make it home to my charger!...and hopefully it will hold a charge.

If it is the battery, and you think you might have trouble riding home, disconnect the headlight (only if it's still daylight, of course ) before heading out.  You can get a lot farther on an almost dead battery if it's not powering the headlight at the same time. 

[76 cb550]

If he road it to work then the alternator should have recharged the battery right?

[750K2]

only if the battery was able to hold a charge.  check the fluid level, the specific gravity etc.  batteries do have a service life due to the charge/discharge cycle.  i get about three years almost to the day from my truck, boat and bike batteries.

[ajinreno]

I rode it around at lunch and it seemed fine. Started right up (kickstart) as well. I agree with a couple of the posts that it probably wasn't the battery (although I was hoping it was something that simple.)

I have a couple other theories. It has shown some flat spots in the throttle doing a similar thing in seeming like its only running on 2 cylinders or starving for gas, but its never died. The tank has flaking paint just inside the rim of the gas cap. I've cleaned most of it out, but I'm sure not all of it...I'm thinking it might be clogging my petcock so I will have to pull that tonight.

The other thing I'm thinking...will it matter how my fuel lines are routed? If they are too long? I put new fuel lines in but ran 2 lines (main/res) into a Y connector and then one line to the carbs. I wonder if the routing is making it hard for gas to get to the carbs.

[hapsh]

The two connectors on the bottom are not Main/Res, they are just two output fittings coming from the petcock valve.  You will be better off running a separate line from each nipple to each dual set of carbs.  I have seen cases of one side clogged and the other side free.  To test them you need to disconnect your fuel lines and plug each side one at a time with the petcock valve ON, you should be able to have a good steady stream of gas coming out of each one.  It is important to have the fuel lines routed so they do not have low points, they should have a steady decline towards the fittings on the carbs.  You can get air bubbles blocking flow if your lines are too long or dipping too low.

[TwoTired]

The fact that the bike had problems at higher speeds/RPM, probably eliminate a battery problem, and makes fuel starvation more likely.

Fuel line routing can be an issue, partucularly when the tank is at low levels, or simply nearing the stand pipe level.  Loops of fuel line usually contain bubbles that can block/restrict flow when the tank head pressure is low.  As the fuel level drops in the carb bowls, the slow jets starve first, leaning those cylinders, idle becomes more difficult if even possible.  Far cylinders from the fuel supply starve first.

Check your filter(s) for debris.  You only need one good one.  But, if it is the capture type instead of the blockage type, trapped particles also reduce the flow capacity.  It's hard to get specific without knowing the year/model of your specific bike.

If the interior coating of your tank is failing, you will continue to have problems until it is addressed properly.

Cheers,

[Gordon]

If it's a fuel starvation problem, make sure the gas cap vent isn't clogged. 

[CrisPDuk]

I never knew that about the SOHC charging system TT, it explains several of the quirks that mine possesses, thanks

The coils need electricity to function.
The alternator on the SOHC4 needs power to make a magnetic field for power generation.
With dead battery, no power for coils = no spark.
With no power to the alternator, spinning the alternator makes no power.

SOHC4 needs a good battery to run.

Cheers,

Well you learn something new everyday.

I was always under the impression that once started, they would run quite happily with no battery at all

I know cars will function this way

Have you ever ran a car with no battery?  Most any modern car will not run without a battery.

Several actually, almost every car I've ever owned has been run without one at some point.  No modern cars will start without a good battery connected, but given a properly functioning alternator they will usually run well enough once started.

[754]

If you are running with headlight on when it starts crapping, and you switch light off & it stays the same.. it is not a battery or charging issue..

[winnipeg550guy]

Well from what I just learned tonight, if you go for too long of a ride with a suspect battery you'll end up pushing it the rest of the way home. I knew the battery was old but pushed my luck because I'm cheap. The RPM's dropped and that was that, couldn't even kick start it.

[754]

I am thinking, with lights off, and adding 6 or 9 volts with like flashlight batteries.. it should be able to kickstart and run..(with points)


 Question being asked as an emergency, get you home or to a town measure..

[ajinreno]

Thanks Hapsh and Two Tired... i'm quite sure now that is the problem. Thanks for setting me straight on the two outlets of the petcock, running two straight lines to the carbs will make it easier to route it correctly as opposed to the current 2 into 1 into 2 setup.

[TwoTired]

My 72 350F will run all day without a battery (lights on).  It won't start without one.  I ressurected this bike from trash and didn't have a battery initially.  I would jumpstart if off of my lawnmower and ride all over the neighborhood terrorizing small animals and old ladies. 

We really need to exploit these areas of the world that defy the laws of physics.  Imagine the technical advantages of being able to generate power without creating magnetic fields, ordinary wire and light radiating elements that self-excite and need no power consumption.  Wow!
Perhaps even gravity and aging can be abated, too.  If we could tap even a small percentage of energy from these perpetual motion machines, we'd have entrepreneurs beating a path to our other-dimensional door! 

I wonder if other unknown aberrational effects can exist in these areas, such as delusional thought and wild exaggeration?   Do I detect the seed of a sci-fi story in the making?  Or, at least, a National Enquirer article!


 

[Gordon]

Gadzooks! Call the National Enquirer......

350F runs without battery; however, I do have very fresh dilithium crystals.

Nice!

What's that idling at?

[TwoTired]

Gadzooks! Call the National Enquirer......

350F runs without battery; however, I do have very fresh dilithium crystals.

Nice!

What's that idling at?

Yes, that, and how much less than stock electrical load do you have?  All LED's?  (DOT approved, no doubt.    )

As long as the alternator is putting out more than what is being used by the system, it will self sustain. (Until the diodes in the rectifier short or fail.)  A stock bike won't run, unless you keep the alternator RPM near peak output.

Electrical budgets are simple equations, you pay out more than you take in, you go broke.  Unless you're the government.

[ajinreno]

So I rerouted the fuel lines so that they go direct to the carbs and are downhill all the way.  Improved performace dramatically. However, it did starve for gas again when i was on the freeway for about 10 minutes. It did it for about 20 seconds where it seemed to run in 2 cyl...then it cleared up. So I'm thinking I might still have issues inside the tank as well, or as someone suggested, maybe my gas cap isn't venting.

[Gordon]

So I'm thinking I might still have issues inside the tank as well, or as someone suggested, maybe my gas cap isn't venting.

Run it until you have those same symptoms, then stop and quickly open the tank cap.  If you hear the sound of air rushing into the tank then it's the vent.