cbr 600 f2

Hey
I have a cbr 600 f2 ' 94 model. The bike was running perfectly when
you open the frottle ,but when cruising at 120k/ph the bike started
jerking. So i cleaned the carbs ect. The bike was standing for about 2
months and now when i drive it it runs smooth but as soon as you go
above 80k/ph or on the highway it starts jerking as if not enough feul
is coming through. I have cleaned the carbs again and the filter in
the tank.Problem persists... Has any one got a remedy to this problem??

 

did it do this before it sat?

Is the jerking rpm independent? That is, does the symptom depend on
speed, or on throttle opening?

Have you done any work to the bike since it started doing this?

Since the bike's sat for 2 months, the obvious culprit is the carbs,
even though you've cleaned them twice. That said, it's usually the idle
circuit that gets plugged up, so it might not be clogged carbs, or it
could be carbs plus something else.

As for the "something else" if you've re-jetted, or (radically) changed
your exhaust, you might be running lean at WoT. Some time on a dyno with
an EGA will tell you more.

I don't recall whether or not the f2 had an inline fuel filter, but that
could be an issue, even more likely if a previous owner had fitted an
aftermarket one.

Finally, (and least likely based on the symptoms given, IMO) is
electrical problems. In that case, however, I'd expect the symptoms
appear based on temperature/run time rather than speed or rpm.

That's what comes to mind immediately, and more-or-less in order of
probability, IMO.

--
Later,
John



'indiana' is a 'nolnn' and 'hoosier' is a 'solkk'. Indiana doesn't solkk.

 

Add 4 or 5 ounces of Berryman B-12 Chemtool Choke and Carburetor
Cleaner to a full tank of gas and go for a slow ride, using as little
throttle as possible.

B-12 costs a little over $3.00 a pint at Wal*Mart.

You'll know the B-12 is working if your idle RPM increases.

You should know where the master idle knob is so you can turn the idle
speed down.

And, if the engine starts running a lot better before you've gone
through the full tank of gasoline, don't go crazy with the throttle,
don't use a lot of RPM before you gas up again.

The alcohol and acetone in B-12 washes the oil film off the cylinder
walls.

 

Sounds like a fuel flow problem. Check the whole system.
Is the tank vent clear? - This can cause a vacuum on high draw rates
and slow the flow.
(Bugs in the vent line are not an uncommon problem. - especially after
long storage.)
Are the fuel taps flowing well?
Are your filters clogged?
Are the lines clear? - (Had this problem on my BMW - new fuel lines
fixed it.
The old ones were damaged internally. It was not apparant from the
outside )
Best of luck,
MadDog - "R75/5 Forever!"

 

Could be something as simple as a partially blocked fuel filter. It
can't flow the fuel it needs at higher rpm.