Changing main jets on carbs NC29
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- Settled in member
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Changing main jets on carbs NC29
I own a CBR400 (NC29) which appears to me to be running lean, the bike is lethargic above 8K in gears 4-6 generally. The bike had previously restrictor discs in the carbs, I assume the jets may also have been changed to suit?
Either way I wish to check the main jets and possibly change them. I have done this once before on an old car which was very easy. However on a bike with 4 carbs it's not something I wish to tackle unless it's something someone says is easy to do (already had an easy comment on the general section), appreciate the positivity CMSMJ1, but forgot there was a workshop section for this sort of query.
If anyone could go through how it's done or show me a your tube clip I would really be grateful. Can the carbs remain in situ?
Regards,
Cosy
Either way I wish to check the main jets and possibly change them. I have done this once before on an old car which was very easy. However on a bike with 4 carbs it's not something I wish to tackle unless it's something someone says is easy to do (already had an easy comment on the general section), appreciate the positivity CMSMJ1, but forgot there was a workshop section for this sort of query.

If anyone could go through how it's done or show me a your tube clip I would really be grateful. Can the carbs remain in situ?
Regards,
Cosy
- Cammo
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Re: Changing main jets on carbs NC29
You need to remove the carbs to do this.
There's a DIY sticky in the V4 section, although the carbs look a bit different the process is the same.
viewforum.php?f=24
Removal and installation of the carbs for the first time will take longer than rejetting them.
There's a DIY sticky in the V4 section, although the carbs look a bit different the process is the same.
viewforum.php?f=24
Removal and installation of the carbs for the first time will take longer than rejetting them.
"It's just a ride" Bill Hicks
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- Settled in member
- Posts: 40
- Joined: Mon Apr 18, 2011 8:06 pm
- Bike owned: 16th bike and still going
- Location: Kent
Re: Changing main jets on carbs NC29
Thank you for that, it was a great help and now fixed. Found it was over fuelling due to a loose emulsion jet on number four.
- Cammo
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- Joined: Thu May 01, 2008 12:35 am
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- Location: Melbourne, Australia