NEED HELP 2003 fazer 600 something like a misfire ???

[Dinger1962]

Nice dry day here today so i thought ideal to take next seasons bike for a quick run as id never been more than couple of miles and i finished all jobs on it.anyhow starts off button perfect--ticks over perfect--accelerates through gears perfect--very fast very smooth --now heres the thing if i am trundling along in traffic in 4th or 5th gear and try to accelerate away the bike sounds like its running on 3 cylinders and has no pull at all drop a gear and it pulls off as it should and continues through gears as normal--never came across this in 20 years riding any info /ideas appreciated thanks--

[daviee]

water in the carbs can do that mine done similar when i first got it but cleared after about 20 miles i put fuel cleaner in it and never had a problem again
 

[Dinger1962]

Thanks will have a look tomorrow--

[darrsi]

I've had a problem recently with water in the system.
It caused starting, rather than running issues though, as moisture tends to settle lower down.
Does the bike run okay under 3000rpm, under normal or low throttle, or is it a bit ropey?

[slappy]

When you say trundling along in 4th or 5th what speed are you doing?  Might be just a case of too higher gear for the speed you are doing, especially as by dropping down a gear  the bike pulls ok.

[Dinger1962]

Hi chaps  bike runs perfect ticks over at low revs drives through gears at all speeds -"trundling along 50-60 mph" 4th or 5th gear try to accelerate away and the bike starts to misfire for want of a better word--this just happening when engine is under load--any other time i can ride up to ton plus through every gear and sustain this speed the bike does not miss a beat ??(maybe should just ride faster )??

[bandit]

How old are your spark plugs.

[Dinger1962]

dunno gonna change plugs and resistor caps see if that helps-

[darrsi]

Chop 5mm off the end of the HT leads then screw the caps back in, it does make a difference.

[Carlsv8]

Sounds very familiar, new plugs sorted my little problem.

[tommyardin]

Nice dry day here today so i thought ideal to take next seasons bike for a quick run as id never been more than couple of miles and i finished all jobs on it.anyhow starts off button perfect--ticks over perfect--accelerates through gears perfect--very fast very smooth --now heres the thing if i am trundling along in traffic in 4th or 5th gear and try to accelerate away the bike sounds like its running on 3 cylinders and has no pull at all drop a gear and it pulls off as it should and continues through gears as normal--never came across this in 20 years riding any info /ideas appreciated thanks--

Trundling along to me would be 30 or 40 MPH, 'In Traffic' sounds almost built up poss 30 or 40 MPH limit. 4 or 5 gear really? bit hopeful expecting a bike to accelerate hard from those sort of speeds in 4th let alone 5th gear, bang it into 3 and nail it. Or if you want to impress everyone 2nd and pop the wheel up on a rapid change down.

[tommyardin]

Ooops! I just read the rest of the thread. been done and said before

[Jules-C]

Also worth checking when the air filter was last changed/cleaned.  You might think it would have biggest affect at maximum air flow with high revs but it has a surprising affect at mid range under load when CV carb is very sensitive to very small changes in intake pressure