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hissing sound at 8-9 rpm

Discussion in 'Technical and Troubleshooting Torque' at netrider.net.au started by devo, Apr 18, 2005.

  1. Hey was considering buying my first bike today. It is a suzuki bandit i brought a mate to have a look at it for me (cos i know jack) anyway he/we noticed that at around 8-9 rpm no matter what gear it is in the engine (or somewhere around there) a hissing noise will happen for a split second then go away. It didnt really seem to make any difference to the way the motor went, itll just make the hissing noise then keep on going. The noise wouldnt stay hissing no matter how hard i tried to keep the revs constant when it started to hiss. Were at a loss as to what it is. Is this normal for this bike?, if not what would it be? will it cost a lot to fix?

  2. Start the bike, let it idle, stick it on the stand, get someone to hold it for you and then cover the the exhaust with your foot (bottom of shoe) or someonething else. If it doesn't stall then...

    It may be a very small hole in the exhaust somewhere which is noticeable only at certain RPM. I've seen it happen before.

    If the bike does stall when you do this then disregard what i just said.

  3. cheers, looks like ill be seeing this guy for the third time lol.
  4. IIRC the Bandit has the same engine as the Across, but with variable valve timing.

    I haven't heard of any Across's doing the hissing thing, could it be the valve timing actuator??

  5. bwahahahahaha :LOL: scared shittles out of me when i bought my bandit.... your on the right track there iffracem, tho the motor isn't quite the same, it is very similar.

    on the 95 models and onwards, you had variable valve timing, thats what your noise is and its TOTALLY normal. and you'll find that if you're heavy on the throttle at the time, you'll feel almost a surge in power at that stage, tonnes of fun :D

    if its a pre 94 model, then it aint got it and then the motor might have some kinda weird alien infestation thats gunna spread each time you hit 9k and eventually take over the planet by splicing the genes of rottweilers, sharks, and velociraptors in a tiny underground lab under your garage :shock:
  6. cool thanks that makes me feel a bit better.... but i dont have a lot of experience with bikes cept the ones i have ridden b4. Would it be normal for a bandit not to have much engine braking? (seemed bugger compared to my mates fzr and the zzr's ive tried) also I didnt really feel any huge rush after that hissing noise. The bike is complianced 1995, which would have to make it pre 95 right? or am i just worried bout jack all.
  7. theres a fair amount of difference between the two, easiest differences to explain without showing you photos, is that the pre95s had clipon handlebars where the post 95s had the MX shaped bars. also, the post 95s SHOULD have the rocker cover painted red (tho it doesn't always stay that way). click the link in my sig, theres a photo of my old 95 model there.

    and i just remember the surge being fairly noticable, would probably feel soft as a sponge now that i've been on a bigger bike for a while :LOL: and engine braking was never much chop on mine but it will lock up the rear wheel still if your riding real aggressively, that motor might be a bit tired tho if its gutsless and has sweet FA braking....
  8. thanks,
    i cant really remember if the handle bars were clipped on or if the rocker covers were red but the bike looked similar to yours ill have to have another look or ask my mate if he remembers.

    thanks again guys appreciate it
  9. the zzr with its sluggish 2-cyl has heaps more engine braking. even the fzr does, although I assumed it was because it's just an old bike.
  10. i'd go with coconuts infestation theory. aust delivery bandits (99 to 2001 ) had a slip cam sprocket ( advances cam timing at 9000 to 9100 rpm) thats what ur noise is . these engines had a few noticeable differences (visual) to the pre 99 models. imports from 96 on used the same engine. as for engine braking try a couple of gears lower (very few engines will brake the bike in the top half of the gear range).
  11. thanks guys