Weird problem....
Guest
Posts: n/a
Weird problem....
CBR 600 F4i 2002
50k
New battery (1 month)
New air filter (2 months)
New Cam chain tensioner (3 months)
New chain (end of last season) (9 months)
New sprockets (9 months)
Bike was running fine....then started jerking randomly a few weeks ago, it was so subtle that I thought it was in my head at first.
Yesterday, rode from work to my moms, didn't notice any jerkiness...left her place, 3/4 of the way home it wanted to die in neutral, was jerky and puttered in gear...managed to make it home by keeping the rpm up but it was running horrible... Home I turned it off and on, it barely stayed alive and idled at 800-900...so I adjusted the idle to 1300, took it for a run and it ran beautifully.
Went to work this morning, no apparent issues, idled fine, think I felt a few small jerks. On my way back (after warming it up and riding a few km's), she was idling near 2000rpm so I scaled it back to 1400 and took continued on my way...definitely felt a few jerks at speed but she idled fine in traffic until I got a few kilometers off the highway (70km/h and lights) and she started puttering, jerking and wanted to die when in neutral.
Got off the bike without letting it die, gave it a couple shots of gas...there was dark smoke coming from the pipe and she sounded like a smoker of 150 years coughing up a lung.... As soon as I let off the gas completely, she died....I then waited a few seconds and turned her back on, she was idling at 1300, no smoke....took her around the block (very small ride), she ran fine...
I'm completely baffled as to what is happening....any ideas?
And yeah...my bike...is a she! :P
Your input is greatly appreciated....
Matt
50k
New battery (1 month)
New air filter (2 months)
New Cam chain tensioner (3 months)
New chain (end of last season) (9 months)
New sprockets (9 months)
Bike was running fine....then started jerking randomly a few weeks ago, it was so subtle that I thought it was in my head at first.
Yesterday, rode from work to my moms, didn't notice any jerkiness...left her place, 3/4 of the way home it wanted to die in neutral, was jerky and puttered in gear...managed to make it home by keeping the rpm up but it was running horrible... Home I turned it off and on, it barely stayed alive and idled at 800-900...so I adjusted the idle to 1300, took it for a run and it ran beautifully.
Went to work this morning, no apparent issues, idled fine, think I felt a few small jerks. On my way back (after warming it up and riding a few km's), she was idling near 2000rpm so I scaled it back to 1400 and took continued on my way...definitely felt a few jerks at speed but she idled fine in traffic until I got a few kilometers off the highway (70km/h and lights) and she started puttering, jerking and wanted to die when in neutral.
Got off the bike without letting it die, gave it a couple shots of gas...there was dark smoke coming from the pipe and she sounded like a smoker of 150 years coughing up a lung.... As soon as I let off the gas completely, she died....I then waited a few seconds and turned her back on, she was idling at 1300, no smoke....took her around the block (very small ride), she ran fine...
I'm completely baffled as to what is happening....any ideas?
And yeah...my bike...is a she! :P
Your input is greatly appreciated....
Matt
Guest
Posts: n/a
Update: On my way to work this morning, ran beautifully until about 1/2 way in where I hit a bit of traffic, then back to 70km/h when she started puttering and jerking again, pulled off to the side, pulled the clutch, dead....started her back up, idled fine, gave it a few shots of gas, dark smoke but not as bad as yesterday, continued on my way, ran well but still felt some jerks and puttering, don't know if it has anything to do but it seems to give a good jerk when hitting big bumps..
Anyone???
Anyone???
Junior Member
Joined: Dec 2011
Posts: 20
Likes: 0
From: Ontario, Canada
The black smoke is from unburned fuel (running rich).
Whenever i've had intermittent "jerkiness" it's been ignition related. Missfiring would also explain the black smoke. I'd look at the ignition system (spark plugs, coils, connections, etc) first.
Whenever i've had intermittent "jerkiness" it's been ignition related. Missfiring would also explain the black smoke. I'd look at the ignition system (spark plugs, coils, connections, etc) first.
If you say it jerks quite a bit when hitting bumps you probably have a short somewhere causing a misfire, if you cant find a short replace your spark plug wires, I had a problem with a dodge Dakota, every left turn i made it started misfiring bad, turns out when making a left turn momentum caused the wires to shift slightly enough to ground out, replaced with new wires problem fixed, your intermittent problem sounds similar to that. Wires may look good, but even the smallest break on the shielding will allow for a short to happen.
Yeah, that's a tough one because it could be a few things. Plug wires isn't a bad guess, though. I had a similar issue with my magna where a wire was arching to the head and causing it to misfire intermittently. I just happened to notice it in the dark one day when I started suspecting it. I wrapped some electrical tape around the plug end and it quit. Made a huge difference in performance.
Sorta sucks that wires are so expensive for bikes, though.
Sorta sucks that wires are so expensive for bikes, though.
Registered Users
Joined: Aug 2013
Posts: 5
Likes: 0
I know this sounds weird (any may easily be nowhere near the solution), but if this should be your problem it's easy and cheap to fix.
Loose battery connectors can cause very strange things. Happened to me once with my old VFR. Jerkiness, sputtering, and funnily enough these seemed to change with different levels of throttle for a while.
You having replaced your battery may also be a clue towards this.
Again, can be a thousan other things, but defo worth a look. It's for free.
Loose battery connectors can cause very strange things. Happened to me once with my old VFR. Jerkiness, sputtering, and funnily enough these seemed to change with different levels of throttle for a while.
You having replaced your battery may also be a clue towards this.
Again, can be a thousan other things, but defo worth a look. It's for free.
Junior Member
Joined: Jun 2015
Posts: 4
Likes: 0
Bringing this post back from the dead because it seems my bike is doing something very similar to this except for the black smoke. I, actually, don't even know if it is or isn't blowing out black smoke but don't recall seeing any smoke when this happens. But the symptoms I'm noticing is the bike starts up & idles just fine at cold conditions. It will also run just fine for a bit but it's always when I'm cruising on the freeway at any given speed and then I'll feel a "sputter" and you can even hear the bike sounds like it's running bad. Once it starts acting like this if I pull up to a stop light with the bike in neutral, as soon as I came to a complete stop it dies, but not every time. Starts back up but start up sounds really weak and like it wants to bog out but then idles back up to the normal idle speed I have it set to. The sputtering will also go in and out so it's not sputtering the whole time once it starts. The way I would describe it is like it's not getting fuel (it's a 2001 F4i with 20.5k miles & no major upgrades) It has a full tank and, yes, I use the high 93 octane at the pumps.
I would consider myself a fair mechanic on bikes. Only been riding for about 14 months now but have worked on cars since 1999 as a self-taught mechanic. Still a lot to learn though.
I would consider myself a fair mechanic on bikes. Only been riding for about 14 months now but have worked on cars since 1999 as a self-taught mechanic. Still a lot to learn though.
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