Starting When Hot

Discussion in 'Supersport (1974-2007)' started by Carr01, May 18, 2024.

  1. 1997 900ss
    Kept on a trickle charger when not used and starts as you’d expect when cold. Cranks over a couple of turns before firing up
    But when it’s hot, after a ride, the engine won’t crank over when the starter button is pressed instead there’s a short pause and then it fires, in a kind of asthmatic burst of energy sort of way.

    Is this normal?
     
  2. No idea if that’s normal, however my old BMW R1150 had similar symptoms which gradually got worse for ‘hot starting’ until it wouldn’t start at all whilst warm. Refuelling proved to be difficult when out on a run until one day I stalled on a junction and was forced to wait until the bike was sufficiently cool enough to start. I replaced the battery in the end and the problem disappeared.
     
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  3. Short answer is NO
    Check all connections and earth points to start with, make sure that the starter relay contractor has clean connections and that the low tension side ( the supply from the starter button) is all good
    It could be the starter motor brushes just starting to give up , give the starter a sharp knock to see if it changes, you can change the brushes in situ but it’s very fiddly
     
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  4. If it's any help, my van had the same. Would start ok when cold but the when hot, starter motor was dead, just a click.

    Obviously the heat and expansion showed the duff starter motor.

    New starter motor and all good
     
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  5. Electrexworld do starter brushes. Sounds like they need replaced. Iirc, about 30 quid.

    Gives starter a new lease of life. They also do new starters. Have you hot beefy starter cables? Helps with our SS's
     
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  6. As Ian mentioned, I’d also suggest up grading the skinny starter and earth cables :upyeah:
     
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  7. Cables have been replaced using Exige’s upgraded set.
    Starter motor brushes however Ive no idea, but at 12’000 miles I’d have thought they would have a bit more life in them.
     
  8. Not really mileage dependent, it more down to how many starts it’s been doing and if previous owners were doing lots of short runs. I replaced my 94 900ss ones with around 18k on the clock, but I had no knowledge of it’s previous history
    If you do replace them it’s a good idea to make up a narrow holding spanner to stop the cable mounting stud from rotating when you unscrew the nut, there’s a small flat section on the stud under the cable , I seem to remember it being 10mm, I made up one from a piece of flat steel, if you don’t the stud can spin inside the starter motor
    I used the Electrux rebuild kit and it’s been working great for the last few years
     
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  9. Don't think I have changed mine on the 94 900 yet.
    As mentioned a thin spanner is most useful and if you can have a practice with an old starter motor, most are similar, it is then fairly easy to do in situ unless you have hands like shovels.
     
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