Gsxr 250 rr

[Mad4lyf]

I have a Gsxr 250RR if you take the tank off after a while the bike starts, revs up, and idles properly. the moment you put the tank on or take it for a ride about 3km the bike dies down and battles to start if it does start you can full throttle it and it will just about idle?? i have absolutely no clue what could be causing this neither does the bike mechanic ... we have cleaned out the carbs about 3 times changed the plugs, flushed the tank and adjusted something with the valves and changed the coils. nothing

Thought it could be something with the air box been squashed by the tank cause when you spray air into the air box with a compressor the revs come right up again

So we tried putting on some individual air filters for each carb and it works for 3km then back to not revving

The next step i think is changing the cdi (could this cause it?)

PLEASE HELP

[Scouse]

Ii have absolutely no clue what could be causing this neither does the bike mechanic ... we have cleaned out the carbs about 3 times changed the plugs, flushed the tank and adjusted something with the valves and changed the coils. nothing

Thought it could be something with the air box been squashed by the tank cause when you spray air into the air box with a compressor the revs come right up again

So we tried putting on some individual air filters for each carb and it works for 3km then back to not revving

The next step i think is changing the cdi (could this cause it?)
PLEASE HELP

Try replacing your mechanic instead of the CDI

[Mad4lyf]

and pay another arm and leg. im sure some1 must knw what could cause this

[220 Ohms]

3kms sounds about the distance you'd get before the float bowls on the carbs emptied.
Is there a pinched fuel line somewhere?

[YellowDog]

and pay another arm and leg. im sure some1 must knw what could cause this

A dodgy choke would cause that effect. Fully close it by hand and see if it goes better.

[saxet]

I've had the same thing, turned out to be a pinched vacuum line between the carb and fuel tap.
Every time I put the tank on it squashed the tube.

[meteor]

I had a similar thing with a vacuum hose, idle but no rev if petcock was set to 'on' but set to 'prime' over rides the vacuum. Maybe look for a pinched or unattached hose.

[Oakie]

3kms sounds about the distance you'd get before the float bowls on the carbs emptied.
Is there a pinched fuel line somewhere?

That would be my guess.

[tigertim20]

dodgy choke, pinched fuel hose or blocked breather hose would be my bet.

and Id start with the breather hose for the tank, air compressor and blow it out. probably your best bet.

[ducatilover]

As already said, Vac line to the fuel shut off or a pinched fuel line. Also, how happy is the fuel filter?
Good luck

[Mad4lyf]

I had a similar thing with a vacuum hose, idle but no rev if petcock was set to 'on' but set to 'prime' over rides the vacuum. Maybe look for a pinched or unattached hose.

We have checked the pipes and none are kinked there's one loose pipe which is the over flow??

petrol flow is normal on prime

[saxet]

Have you had any luck with your fault yet?
When something similar happend to me the kink in the vacuum hose happend as i lowerd the tank into place.
I take it the hoses are clear ( you can blow thru them easily ).
Have you checked the tank breather?
Otherwise it could be a pinhole in the fuel tap diaphram or , as you say an electrical fault.
I work on the theory its most likely to be whatever i was playing with thats the fault.

Is the carb breather hose outlet located in the same place as always?
I have seen weird effects due to a moved breather hose.

Good luck.