nc30 rubber flap under tank

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leerc
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Re: nc30 rubber flap under tank

Post by leerc » Thu Feb 23, 2012 8:29 am

so do both the flaps go dow towards the carb necks under the choke etc

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ibby4585
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Re: nc30 rubber flap under tank

Post by ibby4585 » Thu Feb 23, 2012 8:59 am

Still under discussion. Tried both positions and my old NC performed better with the bottom flap pointing towards the forks resting on the head. But I believe the correct way is flipped back towards V and carbs.

Kris

arsey30
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Re: nc30 rubber flap under tank

Post by arsey30 » Thu Feb 23, 2012 9:40 am

The Honda workshop manual shows it like this.

Image
Image

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ibby4585
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Re: nc30 rubber flap under tank

Post by ibby4585 » Thu Feb 23, 2012 9:52 am

Fairly clear cut then it flips back towards the V.

Cheers Dave.

leerc
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Re: nc30 rubber flap under tank

Post by leerc » Thu Feb 23, 2012 3:15 pm

ill put it right tomorrow

had it out today and it ran like a dream untill it got hot then it ran like a sack of cack-ill put it down to the flap keeping heat in

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Re: nc30 rubber flap under tank

Post by arsey30 » Thu Feb 23, 2012 4:22 pm

I don't think it will make a lot of difference, especially on the move, possibly rich or flooding?
What revs does it play up at.

leerc
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Re: nc30 rubber flap under tank

Post by leerc » Thu Feb 23, 2012 5:04 pm

5-7k iv tried alsorts to eliminate it

carbs out cleaned emulsion tubes checked,pilot screws set back to 2.25
hrc bellmouths out and standard back in
airbox smorkel and rubber flap was missing
changed exhaust
plugs filters
reg/rec

ran really well today untill id booted it and it warmed up it ran crap

wonder if its the heat from the front cyclinders

arsey30
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Re: nc30 rubber flap under tank

Post by arsey30 » Thu Feb 23, 2012 6:15 pm

No, I don't think so, the airbox base plastic extension seals off the rising warm air, so that carbs only take air from between the frame and tank.
The lower rubber flap prevents warm air rising up to warm the airbox [and directs cold air to cool the carbs] but it will only be marginal, the bike would run OK with flap either way round or removed, low speed running would be most affected.
Sounds like a coming off the pilot onto needle problem, [ 1/4 throttle opening?]

leerc
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Re: nc30 rubber flap under tank

Post by leerc » Thu Feb 23, 2012 7:36 pm

full throttle,its always when opeing throttle fully low down

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Cammo
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Re: nc30 rubber flap under tank

Post by Cammo » Fri Feb 24, 2012 12:28 am

The symptoms point towards the bike running lean at that particular rev range.

- Are you sure it's a honda brand air filter that you're using?
- Do you have the correct needles fitted - J51A in rear carbs, J51B in front carbs?
- Are you using the single standard 0.5mm washer on all four needles?
- Are all pilot jets clear and unblocked?
"It's just a ride" Bill Hicks

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