Slight revving issues.

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400baby
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Slight revving issues.

Post by 400baby » Thu Jun 23, 2011 9:12 pm

Right the long and the short of it is, my wife has a H plate cbr400, it runs like and absolute dream. From tick over it pulls clean and smooth all the way to the redline, no flat spots, hesitation, simply its a Honda :grin:
On the other hand my bike, also a H plate cbr400. Tickover is smooth, as soon as you try to pull away its into a flat spot (looses power) then clears itself around 2-2.5k and wants to launch itself into orbit. Not fun, although after riding it for 10 days i did perfect the art of launching myself! Then it pulls fine upto 5k and flats til around 6k (still pulls, just not quite the same urgency :( ), and anything over that and its back to being a Honda! We've changed the carbs, I've not ridden it yet, but if you open the throttle its still not picking up smooth til around 2.5k. Any possible ideas, could it have been cam'd?

DK-Tandy
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Bike owned: CBR400RR NC23
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Re: Slight revving issues.

Post by DK-Tandy » Fri Jun 24, 2011 8:59 am

id say flat spots could be jetting? i could be wrong, but it could be jets or needles causing over fueling and 'bogging' it causing the flat spot.

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BillingCBR
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Bike owned: '88 NC23, NC30, '98 R1, NC35

Re: Slight revving issues.

Post by BillingCBR » Fri Jun 24, 2011 12:28 pm

Best advice is to bung Graeme France an email, he might be able to suggest what to check, he really knows his CBR's :up:
'89 CBR400RRJ and '91 VFR400R NC30 project
Neosophist - The NC30 doesn't go very well when it's on fire

400baby
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Re: Slight revving issues.

Post by 400baby » Fri Jun 24, 2011 6:50 pm

Cheers guys will try GF. As we've changed complete carbs wouldnt have thought about it being jets. But who knows what you get when you buy off eBay!

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