Missing / choking at around 5k?

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CBnick
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Posts: 2
Joined: Mon Aug 12, 2013 9:14 am
Missing / choking at around 5k?

Post by CBnick »

Hi,

My bike runs perfect up until approx 5-6k where is bogs down and chokes with no power but then clears at about 8k.

Any ideas what it may be? It has been standing a while so may need a bit of carb cleaner??

Thanks
TurboPropRoss
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Posts: 5
Joined: Sat Oct 12, 2013 10:56 am
Re: Missing / choking at around 5k?

Post by TurboPropRoss »

Hey there,

Does it miss irrespective of whether being ridden or being in neutral?
J053F
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Joined: Mon Sep 30, 2013 9:23 pm
Bike owned: CB400sf NC31 F-IIr
Re: Missing / choking at around 5k?

Post by J053F »

CBnick wrote:Hi,

My bike runs perfect up until approx 5-6k where is bogs down and chokes with no power but then clears at about 8k.

Any ideas what it may be? It has been standing a while so may need a bit of carb cleaner??

Thanks
I believe this is very common to all CB400sf.
I had the same problem but not that intense. For example, once I was above the "grey area of 6-6.5 Krmp then it was running totally smoothly up to the red area.
Following a carb cleaner + adjustment the choking almost disappeared.
It is still noticable only in case I run at these rpms with the "wrong" gear in, and the engine's torque is not adequate to accelerate fast enough to go above this limit.

Therefore, for me, some cleaning & adjusting should be a good idea.
superv500
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Joined: Wed Apr 24, 2013 9:54 am
Bike owned: CB400, CBR900RRW, CB750
Re: Missing / choking at around 5k?

Post by superv500 »

Try running a bottle of Redex or similar through a tanks worth of fuel. Probably just a bit of dirt in one of the carb circuits.

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