Will a low battry keep an XS11 from starting?

[Mashermoto]

OK...you guys know the project by now...1978 XS1100E. I have two questions...one relating to the battery and the other related to ignition timing.



I finished installing the exhaust today and attempted to start it up for the first time. This is my bike in a box project, so I've never had it running. The engine is completely rebuilt and the only major modifications were a Weisco 1200cc kit, exhaust porting and K&N filter in a stock air cleaner box.

The battery I'm using is a new AGM from Partsnmore.com. However, it did sit unused through the summer, fall and winter. I charged it once in the fall, but let it set again until today.

I measured about 12.3 volts when I began trying to start the engine. It didn't have much crank power at all. After about three short cranks it laid down on me. I latter hooked it up to my Goverment Motors Company truck battery and that helped. But even then I had to rev the truck engine up to get it to crank the XS engine, and that only allowed two or three tries before another wait. I also noted the engine turns over slowly. I don't know if that is a mechanical problem or a result of higher compression from the big bore kit. I think the Weisco kit compression ratio is only 9.5, so that's not much more than stock.

I have the battery on a charger now, and from what I read, I need to charge it to about 14.4 volts for a full charge. I also read that I should have done that when I first got the battery.

The best signs of life I got was a few backfires. Because the ignition system was removed from the bike, I don't know where the ignition should be set. In between time outs for battery charging, I moved the ignition setting back and forth to see if that would help. It didn't.

So question number one. Shouldn't the engine start if the timing is close but not spot on? The ignition plate is set for top dead center, but I don't know how to set the ignition timing with out the engine running so that I can put a timming light on it.

Question number two. Are the ignitions on the XS11 sensitive enough that a low battery will keep it from starting, even if jumped?

Sorry for the long post, but I wanted to give you enough to help with the trouble shooting.

[skippy344]

Be Careful

A truck's charging system is way too powerful for our bikes! All that current could blow out your CDI!

And yes, a weak battery, or a battery with a dead cell, will not start your bike. It has got to be tip-top shape. Especially since it hasn't been running in a while.

Our ignition is not really adjustable. The vacuum advance will make corrections during a pull. If you still have the alignment paint on the plate, you can just reposition the timing governor on the paint swaths.

Make sure your plugs are clean and gapped and she will fire!

[CatatonicBug]

As a test, you can jump from a non-running cage battery. No matter how dead the bike's battery is, the charge in the cage battery will keep the bike running. Just DO NOT START THE CAGE while the bike is connected to it. If the bike is otherwise working, it will start. If it won't start while connected to the cage, there is something else wrong.

[joceiphus]

This sounds pretty stupid, but make sure the switch on your bars is in the RUN position and your petcocks are on. That's usually the #1 thing that I forget!

[clcorbin]

So what is with all this noise about a cars charging system being too strong and blowing out the CDI and such stuff??? Unless these things are wired WAY differently than any other motor vehicle I have ever heard of, that is just silly.

The VOLTAGE coming from the vehicle doing the jumping is limited to around 14.2 V or so by the voltage regulator on that vehicle. Unless that regulator is broken, it will not over volt these bikes as they run with the EXACT SAME TYPE of lead acid battery + charging system + voltage regulator. Yes, I know, there are some differences when charging a AGM versus flooded cell lead acid battery, but for jump starting, those differences are completely irrelevant.

Are the charging systems on the cars much more powerful than what is on these bikes?

Of course they are!

But when you are jumping a vehicle, you are connecting the batteries (and systems) in PARALLEL, not series, so the only thing the jumping vehicle can FORCE is the voltage (if it has the balls. Think dead short on the bike...). It can NOT force any single system to use more current than it otherwise would, it can only hold the voltage higher than the bike's own charging system could. It can just provide the current to keep the batter voltage at it's regulated setting. And given it's more capable charging system, it will do a better job of that than our bike's system ever could (dim lights at idle anyone?).

The ignition system will be pulling current based on this old equation: I = V/R. For the most part, the voltage will be set by the jumping cars voltage regulator minus losses in the cables and the resistance is the resistance of the IGNITION system, not the charging system. Given that it is rapidly turning an inductor on an off, it will also have some impedance as well, but that is not that important in this discussion.

And a bit of real world experience: I have jumped my bike (yes, from a car. Yes it IS a pain in the butt!) on more than one occasion. It still has the factory stock ignition module and other bits working perfectly well. If only I could say the same thing about the timing chain!

One thing that WILL kill the ignition module in a flash (perhaps literally) is hooking up the battery backwards. The ignition module does NOT have any diode protections build into it. If you hook the battery up backwards, parts of the module WILL become a direct short to the "new" ground and they will fry.

So can anyone explain to me how the more powerful charging system on a car will hurt the electronics on these bikes? I can see where they car's charging system COULD damage the BATTERY by charging it too fast (car batteries are generally much large and more capable than bike batteries), but that's not the ignition module...

[DiverRay]

Clint has it correct about jumping a bike. Use ANY 12V. vehicle that is available, and be happy!
As far as a bad battery, YES IT WILL KEEP THE BIKE FROM STARTING OR RUNNING!!! I KNOW this from working on sailors bike! he had a weak battery, and even with a charger plugged in, it would not start. Put in a new battery and it fired right up. NO other changes to the bike.
If the battery cannot keep close to 13.2V charged, it's probably sulfated at least a little. there ARE some options to "fix" this, but I can't remember them at the moment.

[crazy steve]

I find it very odd that even with a battery that's putting out over 12v and a jump, it still wouldn't spin good. How about connections? Is your battery ground connected to clean metal? I see you painted your engine cases; if there's paint where any electrical joint is, that can be the problem. Same goes for the starter; if you had the starter off for repainting, did you remove the paint where the starter bolts to the cases?

Could be a bad starter or solenoid too....

'78E original owner

[skippy344]

Do what you want, but I still maintain that a 75 to 100 amp charging system when connected in parallel, to a 30 amp charging system is not a good practice. Things will catch fire because there are no isolating mechanisms to reduce the charging current.

Minimally, you can explode the motorcycle battery pretty completely.

Just because you can do something, doesn't mean you should.

Two words, Battery Tender.

[Larrym]

Failure to Launch??

Mashermoto,

Gawd!! Doesn't it suck to get this close to the sound and fury yet: DENIED!!


Mechanical:
Ok. Please consider that the newly rebuilt engine has yet to have that necessary oil/fluid in the cylinders and may indeed be a little tight. You don't have to guess about this. By pulling the spark plugs out and turning the engine from the timing plate bolt (Clockwise...) you can feel if it's tight. If it is then I'd say that squirting some marvel Mystery oil (or anything you have handy) into the open holes and then turning the engine over by hand a few times might gain some "ease of motion". Too much mechanical resistance can cause the starter motor to use more amperage, get hotter, and turn the engine over slowly.

BTW: never keep cranking over a few seconds at a time. My rule is about 5 seconds cranking time to 30 seconds rest. These starters do not have any airflow/venting to cool them down after they get used.

Electrical:
Not gonna get into the car battery vs motorcycle battery/charging system debate on the grounds that I may incriminate myself.

You have a multimeter there on the bike and it can lead you to where the problems may be.

1. Place the meter across the terminals of the battery and read the voltage. Hopefully you're doing this in the morning and the battery is fully charged: 12.5 or 12.6 volts DC. Then try to start the bike while looking at the voltage readings.

1a. If the voltage goes down past 9.6 DC Volts while you're cranking then the battery is no good OR the starter is drawing way too much current and pulling the battery down. (If you connect the truck/jumper cables and it still drops down past 9.6 DC Volts then OMG do you have a starter with shorted windings: Fire Hazard!!) Fix: new battery or new starter,

1b. If the voltage doesn't go down and stays at or near the original 12.5-6 DC volts then it is likely that there is a bad connection providing high resistance in the starting circuit which is limiting the amperage flow to the starter. The starter needs those amps to do it's job so if it isn't getting them it will not spin the engine over like it should. Fix: locate bad connection or possible bad starter solenoid.

2. Place one end of the meter on the positive battery terminal and the other end on the starter cable lug. ( Have to remove a cover more than likely...). Now try to start the bike again while looking at the meter readings.

2a. What you're doing is checking for a voltage drop from the positive battery terminal to the starter lug. There shouldn't BE any voltage drop between these two points if the wire is in good shape and the connections are good also. If you read any voltage drop at all then there's resistance/bad connection between these two points. Fix: clean connections.

3. Keep the one end connected to the battery positive terminal and connect the other end to the starter side of the starter solenoid. Again try to crank while looking at the meter.

3a. Your testing for a voltage drop/resistance in the starter solenoid itself. Again if you read any voltage when the meter is connected this way then the solenoid is a problem. Fix: New solenoid or disassemble the unit and try to clean the contacts. (Been done before..)

4. Dude. You may just have bad brushes in your starter. Gotta pull it out of the bike and then disassemble it. I've done that before on lots of bikes but not on any of my XS's so I don't know if the brushes are available. If not then Andreas Weiss be the man to check with for a used one.

General Electrical:

Don't forget the "Engine-to-Frame" ground cable near the middle drive or the battery negative to frame either.

Never...EVER connect 12 volts to a starter which isn't installed and therefore has no load to turn against. Starters are "SERIES" wound and that means that they'll spin up faster and faster (and FASTER!!) to the point where they'll self-destruct.

Hope this helps...I went for a ride today and it just ain't right for you to not be breaking that motor in....

[crazy steve]

...Things will catch fire because there are no isolating mechanisms to reduce the charging current.

Uh, the 'isolating mechanism' is called a voltage regulator....

'78E original owner

[MindWebs]

charging... regulator..... amps.... volts......

Blah blah blah...

12V to 12V, positive to positve negitive to negitive.

if the bikes electrical couldn't handle a jump start my bike would be
in ashes rate now.

i've jumped many bikes and all is well.

just DON'T reverse polarity when jumping, That WILL nuke electronics!!!!
(drunk buddy jumped his beemer, it fryed the computer, i laughed...)

[Mashermoto]

Great advise guys...you gave me plenty of work to do today

Just as an update. I let the battery charge on a cheap bulk charger set at 2 amps over night and this morning I'm reading 14.37 volts. So that's a good thing

I pulled the negative cable off (should have last night when I started the charging) and will check this afternoon to see how much drop in voltage I get. I should lose some as the battery cools down from the charge. Hopefully it won’t go below 13 volts.

There is a very good potential that I have a bad starter, cable connection or solenoid issue. When you get a 30 year old bike in a box and then paint all those parts...only the shadow knows

After church this morning, lunch with the family and take the kids to visit grandma and grandpa (in their mid-80's now), I'll put on my greasy duds, head out to the Man Cave and go through that V=IR and P=IV drill Larry posted

I'll be baaaaaak

[oseaghdha]

I find it very odd that even with a battery that's putting out over 12v and a jump, it still wouldn't spin good. How about connections? Is your battery ground connected to clean metal? I see you painted your engine cases; if there's paint where any electrical joint is, that can be the problem. Same goes for the starter; if you had the starter off for repainting, did you remove the paint where the starter bolts to the cases?

Could be a bad starter or solenoid too....

'78E original owner

If the bike battery has an internal short, it won't let enough juice through to the starter, like Ray sez.

BTDT.

[79XS11F]

Your batteries ability to state your bike has more to do with amperage then voltage. Even a near useless battery will show 12 volts. It's the amperage that does the work. This is why batteries are rated in amp hours, or cranking amps. In any case if the engine will not fire with a jump from your truck something else is at play here. Your bike engine should turn over rather quickly with a jump from your truck.
So, if even while jumped with the truck the engine is not turning over quickly your starter / starting system may need to be looked at.
If it's turning over enough and still not firing, pull all the plugs and hook them up to the leads and lay them on the head. Turn it over and see if you have good blue spark at each plug and also note if the engine will now spin quickly with the plugs out. If still turning over slowly then you know for sure that the starter and or starting system need work. Back to firing, if you have a weak spark you may want to use high output coils that have a bigger gap and larger / hotter spark. Some plugs will not spark when under the added pressure of the increased compression ratio.
If all ignition system appears good to go, then your needing to look at the fuel supply. Did you smell fuel when you pulled the plugs? Were the plugs wet with fuel?
Rob

[Mathh]

Just a thought...have you checked the earth cable and its connections (free of paint) between engine and frame, they can corrode to the point of no connection. your engine will never start with this cable not intact..