CBR 400 nc23 holding back until upto revs

does anyone know why my bike holds back until getting to medium revs then goes like stink ...if i wind the throtte back slowly it will go fast but if i wrench the throttle back fast bike just makes a booorrrrrrrrr sound before picking up and absolutely ripping my head off i have just no bottom end.. sluggish until it get going...power all top end

the help would be really appreciated

sounds like your not gettin the right air/fuel mixture when giving the throttle some, id get it on a dyno go from there.

Adam

Def. fuel related? Have you done any work to it recently?

veefer400 wrote:Def. fuel related? Have you done any work to it recently?

yes put in bigger jets. it was like it when i bought it, i put in bigger jets to try and cure it but no difference

have you give carbs a good clean out?
anything blocking the fuel line?
anything blocking the air flow?
is the fuel filter and pump in good working order?

the jets mr france sent yo should of sorted it out, so i would check everything, fuel lines, air flow, pump, filter.
If there is any bits of crap in the fuel filter it wont be able to pass the fuel through it efficiently which will end up with fuel starvation, if the air flow is blocked then as you give the throttle a good go there will be plenty of fuel coming through but not enough air to counter act the fuel which will make it bog down.

From the sound of it your saying it is ok if you slowly open the throttle? which does suggest something some were is blocked or trapped or needs a good clean. As you slowly open the throttle if something is blocked or not letting much fuel/air through it will be ok but soon as you give it some its all going to get trapped and not pass through as quick as it should.

Hope this helps mate. if i was close to cambrige i would give you a hand lol.

Adam

petrolhead19 wrote:have you give carbs a good clean out?
anything blocking the fuel line?
anything blocking the air flow?
is the fuel filter and pump in good working order?

the jets mr france sent yo should of sorted it out, so i would check everything, fuel lines, air flow, pump, filter.
If there is any bits of crap in the fuel filter it wont be able to pass the fuel through it efficiently which will end up with fuel starvation, if the air flow is blocked then as you give the throttle a good go there will be plenty of fuel coming through but not enough air to counter act the fuel which will make it bog down.

From the sound of it your saying it is ok if you slowly open the throttle? which does suggest something some were is blocked or trapped or needs a good clean. As you slowly open the throttle if something is blocked or not letting much fuel/air through it will be ok but soon as you give it some its all going to get trapped and not pass through as quick as it should.

Hope this helps mate. if i was close to cambrige i would give you a hand lol.

Adam

were are you? can you balance the carbs because there leaking fuel now so need to replace seals on carbs so all got to come off again anyway and would rather have someone who's a bit clued up help

3 hours 35 mins
to preston oh ok nevermind lol

lol yeah its a fair bit travel from preston lol.
and yeah i can balance carbs lol.
carb balancer isnt that much money though, it is a little tricky balanceing them the first time but bit of patience and you will work it out, and im sure there is a "how to" on the forum some were telling you how to balance them.

Strangely enough my nc23 started doing the same on me last night, when open the throttle fast it bogged down , but i think thats because my valve clearances need doing which ill be doing soon.

Adam

petrolhead19 wrote:lol yeah its a fair bit travel from preston lol.
and yeah i can balance carbs lol.
carb balancer isnt that much money though, it is a little tricky balanceing them the first time but bit of patience and you will work it out, and im sure there is a "how to" on the forum some were telling you how to balance them.

Strangely enough my nc23 started doing the same on me last night, when open the throttle fast it bogged down , but i think thats because my valve clearances need doing which ill be doing soon.

Adam

if you replace my carb seals and balance my carbs il give you 150 for doing it u gotta come ere though lol

just to let everyone know my emaultion jets were blocks with silicone from a bad mechanic in cambridge and all is sorted now fixed by some very amazing bike mechanics called piston broke motorcycles in cambridge £45 for carb clean and new seals including labour good lads......thanks for all help in getting my bike sorted XXX