CBR 400 nc23 holding back until upto revs
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- Settled in member
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- Bike owned: cbr400 nc23/derbi senda 50
- Location: cambridge
CBR 400 nc23 holding back until upto revs
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
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
- petrolhead19
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Re: CBR 400 nc23 holding back until upto revs
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
Adam
xivlia wrote:because i can smell and see petrol squirting out from the exhaust. like little droplets
porndoguk wrote:That will be condensation, if you think its petrol get a lighter bellow the exhaust and see what happens?
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Re: CBR 400 nc23 holding back until upto revs
Def. fuel related? Have you done any work to it recently?
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- Bike owned: cbr400 nc23/derbi senda 50
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Re: CBR 400 nc23 holding back until upto revs
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 differenceveefer400 wrote:Def. fuel related? Have you done any work to it recently?
- petrolhead19
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Re: CBR 400 nc23 holding back until upto revs
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
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
xivlia wrote:because i can smell and see petrol squirting out from the exhaust. like little droplets
porndoguk wrote:That will be condensation, if you think its petrol get a lighter bellow the exhaust and see what happens?
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- Bike owned: cbr400 nc23/derbi senda 50
- Location: cambridge
Re: CBR 400 nc23 holding back until upto revs
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 helppetrolhead19 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
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- Settled in member
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- Bike owned: cbr400 nc23/derbi senda 50
- Location: cambridge
Re: CBR 400 nc23 holding back until upto revs
3 hours 35 mins
to preston oh ok nevermind lol
to preston oh ok nevermind lol
- petrolhead19
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- Bike owned: 2 x nc23's 1 x nc29
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Re: CBR 400 nc23 holding back until upto revs
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
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

Adam
xivlia wrote:because i can smell and see petrol squirting out from the exhaust. like little droplets
porndoguk wrote:That will be condensation, if you think its petrol get a lighter bellow the exhaust and see what happens?
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- Settled in member
- Posts: 36
- Joined: Wed Apr 28, 2010 10:21 pm
- Bike owned: cbr400 nc23/derbi senda 50
- Location: cambridge
Re: CBR 400 nc23 holding back until upto revs
if you replace my carb seals and balance my carbs il give you 150 for doing it u gotta come ere though lolpetrolhead19 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
-
- Settled in member
- Posts: 36
- Joined: Wed Apr 28, 2010 10:21 pm
- Bike owned: cbr400 nc23/derbi senda 50
- Location: cambridge
Re: CBR 400 nc23 holding back until upto revs
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