won't rev past 6k???

[Diabolus]

My friends Gsf 600 bandit starts fine and revs freely on the stand, but when ridden as soon as you hit 6k in any gear it stutters and will not pull anymore.

Just trying to get some ideas where to start, all I have done so far is pulled the plugs to check colour and they seem fine and took it for a ride it will bearly hit 80mph when it should hit 120mph+.

It's a 53 plate with 33k on the clock, she has had this problem ongoing for a while and has already paid for Carb cleaning and new plugs and coils which hasn't made any difference.
I know it's either fueling or an electrical issue.
It has an aftermarket can and airfilter but ran okay when they were first fitted.

Any ideas please.?

[lloydie]

Fit a standard air filter for starters .
Has it got a standard air box ?

[Watty]

I'd go fuel starvation! Blocked/restricted tank/inline filter?

[fabiostar]

or poss breather in the tank cap airlocking it

[lloydie]

Could be low compression !

[Diabolus]

I don't think it has standard air box. it looks like someone has moded it there is a tube that is cable tied above the battery that doesn't look standard.

[Diabolus]

or poss breather in the tank cap airlocking it

I forgot to check this when I rode it earlier today, could have opened filler cap to check.

what puzzles me is that it revs freely on stand, if it were a fueling issue would it not affect it?

[Diabolus]

Could be low compression !

if it was low compression it would affect it lower in revs too? it pulls strong until 6k

[Diabolus]

or poss breather in the tank cap airlocking it

I forgot to check this when I rode it earlier today, could have opened filler cap to check.

what puzzles me is that it revs freely on stand, if it were a fueling issue would it not affect it?

breather could be blocked, she leaves it outside with out a cover.

[lloydie]

I had a similar problem when I street fighter my cbr6 it had to much air being forced into the air box and at 6k under load it would splutter and loose power .
I fitted a deflector to stop "ram air" and it worked a treat .

[Diabolus]

I had a similar problem when I street fighter my cbr6 it had to much air being forced into the air box and at 6k under load it would splutter and loose power .
I fitted a deflector to stop "ram air" and it worked a treat .

it's a k and n air filter, could be too free flowing then.

[lloydie]

Yes if you try a standard on it'll rule it out . There cheap do could be a cheap easy fix

[Watty]

Yes if you try a standard on it'll rule it out . There cheap do could be a cheap easy fix

Not sure it can be the filter as it was running OK when first fitted! Worth a try though

[AMCQ46]

If the bike was running ok and now isn't, we need to know what has changed. Any more history on what happened between last time it was ok, and now?

[fabiostar]

or poss breather in the tank cap airlocking it

I forgot to check this when I rode it earlier today, could have opened filler cap to check.

what puzzles me is that it revs freely on stand, if it were a fueling issue would it not affect it?

when its sitting on the stand it will rev ok because its not pulling any load. from the description id say the ignition side is ok its a fuel problem. K&N filter if it hasnt been jetted its prob running weak when its comming onto the main jet..it will be worse in winter when the air is cold and it runs even weaker.