Topic: Top End Work Complete - Bike Won't Start

[dave500]

negative,,a battery wont be fully charged on the interstate in 20-30 minutes,give your charging system a check over,also make sure there is no discharge with the key off.

[mbspark]

Short Story
New stalling issue in summary: Bike will stall when idling for longer periods of time. Wont' start right away. Will start after 20 min of waiting (sometimes). I can ride bike if I keep rpm's above 3k the entire time, but then it won't start if I shut it off.

Long Story
There is a slight discharge of the battery while just sitting in the bike. Over the course of a week I've taken different readings and it's gone from 12.5 down to 10.8. But this includes rides as well.

The latest issue I find interesting. I was riding the bike downtown in bad traffic, the bike ran for about 20 minutes and then stalled out at a light. I pushed it up on sidewalk to get out of terrible traffic.

I took a 20 minute walk to drop off paperwork, came back to the bike, had a talk with a homeless lady looking at the bike. I told her I was going to move it away from her cart to a parking lot so I could come back with my truck and pick it up, but for grins I try to start it, and bam on first kick it starts. Ride it 2 minutes to safe location, shut it off and call my buddy who was coming to pick me up. I tell him I don't need picked up, the bike starts but come anyways to follow me home. Bike won't start again. Buddy shows up, we push the bike down a ramp and bump start it. I ride the bike home keeping rpm's above 3k. Felt like the movie speed    Get home, check plugs thinking I may be running too rich. Plugs are perfect and dry as can be, nice tan color. Bike won't start back at my house. 1 hr passes, still didn't start and haven't tried since.

Can't figure out this sporadic stalling, not starting, then starting issue. Battery has maintained over 10v the entire time.

[gsnorcal]

"over 10V" is not acceptable. It should be over 12V at all times. Maybe just over 13 right after charging. Probably 12.7-12.5ish with no load.

You have a battery/charging/phantom load problem somewhere.

[mbspark]

I just went out and looked and now the battery read 11.3. This is after 10.8 yesterday after pulling it in the garage. Makes no sense.

My old man told me old motorcycles should technically be able to run without a battery. I'm sure that is not a true statement?

So a battery with level 10.8 could case the bike to stall out at idle revs?

[gsnorcal]

Spark == electricity. No elec == no spark. So, yes, it can die on you. Our bikes need a battery to run. Search for "remove battery" and you'll see threads. We don't have a permanent magnet in our charging system, so they need current to create the field which then allows generation of electricity.

There are a bunch of ways to attack this problem. You need to rule out potential problems one by one.

1) This Electrosport troubleshooting guide, or one from a Honda service manual, can be useful. But you need to sort out the stuff that isn't relevant for your bike. http://www.google.com/url?sa=t&source=web&cd=2&ved=0CCkQFjAB&url=http%3A%2F%2Fwww.electrosport.com%2Fmedia%2Fpdf%2Ffault-finding-diagram.pdf&rct=j&q=electrosport%20troubleshooting&ei=Et5iTr6lHuTkiAKsmLy8Cg&usg=AFQjCNHa9xof4ktD5lR33em2QokoNJNVlw&sig2=Q6nTRhQbb4ffrp8gOluyhg&cad=rja

2) Remove and charge the battery. Bring it to an auto parts store and have them load test it. Then you will know if it's good or bad. If it is good, you probably have a charging problem.

3) With the key off, check the battery voltage. Then disconnect the battery leads and check the voltage. If they are not the same, then you have a phantom draw that you need to find. Removing fuses one by one can isolate the draw. Or use a clamp-type ammeter which you can clip around wires to see if current is flowing down that specific path. $50 unit from Sears works good enough.

Hope that's enough info to get you started.

[mbspark]

Thanks for the tips!

I will be spending the next 2 days trying to figure this thing out.

[TwoTired]

I just went out and looked and now the battery read 11.3. This is after 10.8 yesterday after pulling it in the garage. Makes no sense.

Yes, it does.   A good battery will "self recover" somewhat as the chemicals inside redistribute while resting.  Batteries don't store electricity, the energy is produced by a chemical reaction inside.  A reverse reaction is created when power is supplied to a lead acid battery.
You need to supply more energy to your battery to make the full reverse reaction complete.

My old man told me old motorcycles should technically be able to run without a battery. I'm sure that is not a true statement?

Depends on the motorcycle.  The alternator on the SOHC4 is excited by an electromagnet instead of a permanent magnet.  So, it needs battery power for it to make power, plus rotation.  Permanent magnet generators/alternators only need rotation to make power.
Further, the standard electrical load exceeds the alternator capability at idle rotation speed.  So, the bike takes power from the battery at those RPMs.  Normally, the battery is restored when the engine RPM is increased where it can supply the bike electrical load plus place energy back into the battery.

So a battery with level 10.8 could case the bike to stall out at idle revs?

Yes, the coils need power to make spark.  The lower the voltage to the coils the weaker the spark.  At some low voltage point, the coils can't produce enough voltage to make a spark.

[mbspark]

I decided to start with a new battery. Had a guy test the old one at Pep Boys. He didn't seem to know what he was doing, but said the battery was bad. I figured, screw it, I will just get a new one and rule out the battery as being the issue.

With new battery installed, I ran the charge test. All results were great @ 2500rpm and at 5000. I took it for a spin to the post office and back with about 30% idling 70% driving of the time the bike ran for this little 10 min trip. The battery read 12.8 when I got home.

So maybe all of this was a bad battery. I am going to take the bike to work tomorrow along with my multimeter and see if my luck of it running continues.

Now I just need to do a search on here and see why the turn signals won't blink when pressed far to each side of the switch, but will blink when only pushed halfway to each side.

Thanks all again for your continued help in my drama