Welcome to Netrider ... Connecting Riders!

Interested in talking motorbikes with a terrific community of riders?
Signup (it's quick and free) to join the discussions and access the full suite of tools and information that Netrider has to offer.

CBR600 problems when cold

Discussion in 'Technical and Troubleshooting Torque' started by wokka wokka, May 31, 2011.

  1. OK, here’s my problem, which I thought I’d throw there to internet land for any ideas and to see if anyone else has had a similar problem.

    Cold engine, choke full on.
    Bike starts, runs for up to 3 or 4 minutes (long enough to do up jacket, put on helmet and gloves and get up to 1km down the road).
    Revs start to decay. (if riding you can feel a hesitation, especially if applying power, it pauses then sluggishly takes off)
    Bike stalls.
    Takes anywhere from 1 or 2 starts, to up to 10 minutes of trying, to get bike running. When doing this it either stalls immediately, or runs for up to 20 seconds at very low revs (approx 600 rpm). If choke is not on full, it won’t run at all. Touching the throttle while running causes instant stall.
    When the bike decides to work, revs will climb quickly to over 3000 rpm (what I’d expect with a warm engine and full choke).

    On a couple of occasions the revs have started to drop, but then recovered to over 3k, so it never got the point of stalling. As I said, sometimes I can get it going pretty quick, others it takes 10 min, or longer on one occasion.

    Once the bike is running I can reduce/shut off choke and it will be fine, runs as normal.

    This used to only happen after long periods of not being ridden (if I was away for over a week), but in the last couple of months has happened a bit randomly. Last week it happened on Thursday and Friday evening, but had been fine in the mornings. Last night I had to get the RACV to get a flat bed to get the bike home, it just refused to start. I ended up with a flat battery, RACV man tried with his power supply connected for a while, still no go.

    Bike is serviced by Pete at Everything 2 Wheels (major service was at the end of March), and I’ll drop it back into him when I can get it going/towed, but he was a bit mystified on Sat when he gave it a quick look.

    Bike is a 1999 Honda CBR600F (carbies, not Fuel Injected), has done about 50k km. I use it as my daily transport, and apart from this problem its been pretty good for the 2.5 years I had it.
  2. Sounds like you might be keeping the choke on too long and it's making the fuel mix too rich.... I'd turn the choke off just when the temp guage is just above the first marker.. You may have fvcked your plugs from leaving the choke on when not needed...
  3. I would turn the choke off, but the temp gauge doesn't get to the first marker before the bike dies.

    Managed to get it to the mechanics this arvo, it started, looked like it was going to die as it stumbled along at about 900 rpm, then after a couple of minutes of stumbling, the revs shot up and it was fine. The revs shoot up when the temp starts to get to the first marker, at which point I can shut the choke off, if I shut the choke off any earlier it'll die.
  4. #4 99CIBBER, May 31, 2011
    Last edited by a moderator: Oct 24, 2015
    Let us know what your mechanic says. Cheers
  5. I'm curious about this one as well.
  6. Heard back from Pete (the mechanic) today, turns out to be the fuel pump.

    The bike runs for a short while on the fuel in the carbies, then shuts down.
    Sometimes the application of power will jolt the pump and give some fuel,
    hence the runs a bit then stops when trying to start, and just won't start
    on other times. Once the engine warms up it frees up the pump a bit and it
    starts working. So with it being intermittent when cold (and seized)
    explains why it starts better sometimes than others.

    He's now trying to source a pump for me, might be a job with the restricted operation of the Japanese factories etc. (electricity rationed to 3 days due to the nuclear plant being out of action)

    Anyway, another top job by Pete at Everything 2 Wheels.
  7. You might be able to source something second hand at VicWreck in Heidelberg
  8. Thanks for the update Woka
  9. Ok, next question...

    Does anyone know where I could get a new (or 2nd hand) fuel pump?

    VicWreck don't have any, Pete can't find one in and would have to order one from japan (so about 4 weeks), even eBay isn't any help.

    I've emailed a couple of places in the USA to see if they have any, but that will still take a few days.

    The bike is normally my daily transport, so I need it fixed to get to work on. Shame this fuel pump only seems to have been used on the '98 and '99 CBR600Fs, no other Honda bike.