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Bike Problem?

Discussion in 'Technical and Troubleshooting Torque' at netrider.net.au started by nodz, Feb 26, 2005.

  1. I was wondering if anyone could help me, I'm not sure whether I've got a bike problem or its the way I ride it or whether it's not a problem at all, but the symptons are rather hard to describe.
    This morning after I'd ridden about forty kilometres I'd stopped at a shop, dashed inside to buy something and came straight out again. I went through bike preps and started the bike. Bike was in neutral and ticking over about 1500rpm (what the manual says is correct). I pulled in the clutch and put the bike in first (definitely first, as I put the gear level 1 click down and the neutral light extinguished, and this is definitely not a race pattern gearbox, so I didn't accidentally put it into second) I let the clutch out gently as I felt it take up and wound the throttle back to increase the revs of the engine (about the same amount as I normally do for a nice controlled take-off). The bike started to move and was sort of bouncing funny (that's all I can do to describe it). It was almost as though I was trying to take-off in thrid gear. I think I had plenty of revs, as I said about the same amout as I would normally have for a take-off. The clutch was not just let straight out, it was gradually released in a controlled manner. Anyone suggest anything?

  2. 1500 rpm seems a bit low for most 250s let alone a heavy mutha like a CB250. I did a HART course on one of those a while back and we would generally crank them to at least 3000 before easing the clutch out - using it to control the take off.

    The shuddering you experienced was your bike in the early stages of stalling
  3. 1500rpm is idle speed only, while in neutral. Your right about 2500 rpm as the clutch is start to be let out.
    Don't think early stages of stalling. Exactly the same take off as normal.
  4. Nodz, did the problem continue or was it only on that one occassion starting from stationary?
  5. Happened to me three times. The first time I thought it was a stall, pulled in the clutch, gave it a bit more and slowly release cluth, problem still there. I changed to second at about 20kmph (which is about right for my bike) problem continued for about two seconds then gone.
    Second time it happened was on a hill start, going up a steep driveway. Gave it more that I knew would have to and problem occurred.
    Third time changing down gear, pulled in clutch changed down to third gear at about 25-30kmph which is what the manual says for my bike and problem started. I was still braking to below 20kmph and changed down to second and problem was still there. Came to a stand still at and intersection, changed to first. Took off, problem not there.
    Could it be a slack chain. I've sat someone on my bike and there was about 20-30mm pf play, which is what the owners manual says there should be.

    I'm preety sure its not a stall, if I take off get up to second, then snap throttle closed and foot on back brake (slow ride technique) I don't really have to touch clutch, the bike doesn't want to stall.
  6. Try draining your carby/carbies, if you have had a batch of contaminated or stale fuel this can happen
  7. thats what i was gonna say...
    only use fuel from either Caltex, mobil, shell or BP, don't trust any of the other servos.
  8. Interesting you mentioned the chain. Same sort of thing happened to me last night. Felt like most of the time i was trying to pull too tall of a gear. When i got home had a quick look( i dont know much about bikes, only just started riding) and the chain seemed to be quite loose. It was at night so i didnt measure it or nothin and im not sure what its suppose to be anyway. Done a few return trips sydney to albury since i bought my bike and not sure when the last service was so i think ill just do a whole service on it anyways.
  9. That's possible considering all the recent rain in vic. lately. Another possibility could be your spark plugs. Any idea how fresh they might be.

    A slack chain won't affect engine running or cause stalling.

    Its a bit hard troubleshooting over the net. If this is only happening on the release of the clutch, it may be a clutch problem.