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Why did my bike start this morning?

Discussion in 'Technical and Troubleshooting Torque' started by Fa1c0n, Aug 1, 2014.

  1. After riding home in the rain last night I accidentally left my headlight on for about 10-15 minutes without the engine running. This morning I wheeled the bike out onto the road and hit the go button... "Rrrr.........Rrrrrtt...... Rrr...... Rrrrt" not a good sign. Seemed the battery was dead, gave it another shot, slowly turning over, not starting.

    Well I had better roll start it - So I slowly made my way up a very gentle incline pushing the 270kg Harley Davidson to the top. Well, that was tiring.

    I pointed the bike down the road, turned the key, put it in second gear and pulled in the clutch. I started running down the very small incline, so much effort, got about as much speed as grandma making her way to the bingo table - jumped on and dropped the clutch.

    The bike stopped immediately and didn't turn over - I was not going anywhere nearly fast enough for the 1200cc engine.... Well fcuk, better call roadside assist for a jump - But I will try to start it just one more time.

    I pressed the go button as I did earlier, expecting the same pathetic whine and not to start - but this time it fired up straight away "CUUUHHThummmmmm potatopotatopotatopotato" and away I went.

    My question is - why did it decide to start the second time around? Did the 100 metres I pushed it somehow charge the battery? Did the shitty roll start I attempted lubricate the piston enough for the weakened battery to move it?

    If it didn't start the first time, how did it start the second?
  2. My best guess is that the puch start gave the battery enough shaking andd sloshing of the battery acid that it generated some additional charge on the plates. Being a lead/acid battery, that shaking may have created enough chemical reaction to give it a bit more charge. If you didn't go for a long ride, then you should put the battery on charge overnight.
    • Agree Agree x 1
  3. Interesting thought about the battery... It was odd though, because it didn't struggle at all when I tried again. Literally first press, started right up - like a new battery.

    40km to work + some highway. She'll be right.
  4. Well if it started strongly, I'm guessing that the 10-15minutes didn't flatten the battery enough, but rather you have a bad connection.

    The rain highlighted it. Check and clean the battery and solenoid connections.
  5. Very possible. My mate has a similar model and he had this exact problem, I had forgotten about that. Ill double check tonight!
  6. I'll vote with Senetor. In days of old it was common to give the battery a sharp tap with a hammer on cold mornings to give yourself the best chance getting it started first go.
    "Rrrr.........Rrrrrtt...... Rrr...... Rrrrt" means it wasn't dead flat. If it was it would have made a clicking sound. Or nothing.
  7. Perhaps it finally blew the potato out?

  8. Next time try clutch starting in4th or 5th gear.
  9. Really? Would it actually start?
  10. The roll start might have pushed just past TDC. Then the starter sucked in enough juice and gave the flywheel enough speed to get a spark and vroom?
    Definitely check the battery terminals for being tight and clean too.
    • Like Like x 1
  11. I remember Dr Karl used to say that blasting the horn 'could' get a flat battery to generate enough charge to start the engine.

    I've never been able to do it.

    Whatever you did must have just given it that extra 5% to get it over the line.
  12. She wouldn't go again this morning. Not even my petty roll start attempt helped. Even tapped the battery... No dice.

    Got a jump from roadside assistance and bought a battery from PS.
    Hopefully my problem is solved.
  13. You own an pushrod harley... Your problems are only just beginning ;-)
  14. This one's just go extra push at the moment.
  15. My guess is that the weakened battery wasn't strong enough to overcome the stiction in the clutch plates and engine bits due to the cold oil. Your roll start attempt freed up the moving bits and "hey presto" the battery was able to turn over the freed up engine.

    I learned this recently in the UK, but it's considered good "ridermanship" to always start your bike in nuetral. to reduce the wear and tear on the battery and starter motor. Just pulling in the clutch is not considered enough. Which reminded me of my Stayupright L's course years ago, which taught the FINECC starting procedure, (Fuel on, Ignition on, Neutral gear, Engine cutoff switch on, Choke on, Clutch engaged)... not quite as relevant on modern EFI bikes, but you see the point.
  16. I never really considered that he might be trying to start the bike, in gear, with the clutch in. It's not something I ever do, unless it's a hot start, after a stall.
  17. I only ever start in neutral.
  18. There's no guarantees with push starting but yes, 4th would probably be more effective than 2nd. I always default to 3rd gear when push starting anything. :)
  19. Thanks for the tips. The roadside bloke who had a HD said it would take 4th, too.