nc21 performance prob. above 4k rpm.
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- Settled in member
- Posts: 15
- Joined: Sat Apr 17, 2010 9:29 pm
- Bike owned: vfr nc21
- Location: greece
nc21 performance prob. above 4k rpm.
Hi!
My nc21 has poor performance after passing 4k rpm.
I dont know what happened. something like can't breathe.
At idle it works ok, not hanging. all starts after passing 4k rpm.
any advices?
valve clearences?
main jets?
sorry for my bad english...

My nc21 has poor performance after passing 4k rpm.
I dont know what happened. something like can't breathe.
At idle it works ok, not hanging. all starts after passing 4k rpm.
any advices?
valve clearences?
main jets?
sorry for my bad english...
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- Moderators
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- Joined: Fri Jul 04, 2008 1:01 pm
- Bike owned: CBR954
Re: nc21 performance prob. above 4k rpm.
Did it suddenly start?
It's not likely to be main jets if it just start.
Electrical system (is battery charging?)
fuel system.. is vaccum pipe from tank to cylinders ok?
It's not likely to be main jets if it just start.
Electrical system (is battery charging?)
fuel system.. is vaccum pipe from tank to cylinders ok?
xivlia wrote:i dont go fast on this bike so really do not need a rear brake.. /
vic-vtrvfr wrote:Ask xivlia for help, he's tackled just about every problem u could think of...
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- Settled in member
- Posts: 15
- Joined: Sat Apr 17, 2010 9:29 pm
- Bike owned: vfr nc21
- Location: greece
Re: nc21 performance prob. above 4k rpm.
yes it starts suddenly...
battery charging ok.
vaccum pipe ok... i dont know what to do...
battery charging ok.
vaccum pipe ok... i dont know what to do...
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Re: nc21 performance prob. above 4k rpm.
not likely to be jets then.
Was it standing a long time before the problem start? if it was not then carburettor problem is not likely.
Have you tested electrical system with multimeter? They are known to have problem.
Test the battery voltage at idle and at 5000rpm, with and without headlight
Was it standing a long time before the problem start? if it was not then carburettor problem is not likely.
Have you tested electrical system with multimeter? They are known to have problem.
Test the battery voltage at idle and at 5000rpm, with and without headlight
xivlia wrote:i dont go fast on this bike so really do not need a rear brake.. /
vic-vtrvfr wrote:Ask xivlia for help, he's tackled just about every problem u could think of...
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- Settled in member
- Posts: 15
- Joined: Sat Apr 17, 2010 9:29 pm
- Bike owned: vfr nc21
- Location: greece
Re: nc21 performance prob. above 4k rpm.
No it's not standing for a long time.
I test the battery tomorow... I have fitted bigger battery from a yzf r1 (jel) 10A. I dont do it right?
I test the battery tomorow... I have fitted bigger battery from a yzf r1 (jel) 10A. I dont do it right?
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- Moderators
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- Joined: Fri Jul 04, 2008 1:01 pm
- Bike owned: CBR954
Re: nc21 performance prob. above 4k rpm.
the smaller battery is ok, the problem is usually the charging circuit stops working so the battery doesnt work properlytragos wrote:No it's not standing for a long time.
I test the battery tomorow... I have fitted bigger battery from a yzf r1 (jel) 10A. I dont do it right?
xivlia wrote:i dont go fast on this bike so really do not need a rear brake.. /
vic-vtrvfr wrote:Ask xivlia for help, he's tackled just about every problem u could think of...
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- Settled in member
- Posts: 15
- Joined: Sat Apr 17, 2010 9:29 pm
- Bike owned: vfr nc21
- Location: greece
Re: nc21 performance prob. above 4k rpm.
i still have tha same problem, and now not fairing at all..
no spark at any cylinder....
no spark at any cylinder....
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- Bike owned: VFR400
- Location: Blue Mountain NSW Australia
Re: nc21 performance prob. above 4k rpm.
Are you using original battery still, what is the voltage.
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- Settled in member
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- Joined: Sat Apr 17, 2010 9:29 pm
- Bike owned: vfr nc21
- Location: greece
Re: nc21 performance prob. above 4k rpm.
yes i am on original battery now.
voltage 14.5v at 5000rpm, a litle bit lower at idle...
i found water in my spark unit!! i think thats the problem!
is there a way to fit a nc24(rh) spark unit to my nc21(rg)?
nc24 has 3 wires les than the nc21.
nc21 has a camshaft sensor.
voltage 14.5v at 5000rpm, a litle bit lower at idle...
i found water in my spark unit!! i think thats the problem!
is there a way to fit a nc24(rh) spark unit to my nc21(rg)?
nc24 has 3 wires les than the nc21.
nc21 has a camshaft sensor.
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- Moderators
- Posts: 8172
- Joined: Fri Jul 04, 2008 1:01 pm
- Bike owned: CBR954
Re: nc21 performance prob. above 4k rpm.
I dont' think you can fit it easily.. get an NC21 spark unittragos wrote:yes i am on original battery now.
voltage 14.5v at 5000rpm, a litle bit lower at idle...
i found water in my spark unit!! i think thats the problem!
is there a way to fit a nc24(rh) spark unit to my nc21(rg)?
nc24 has 3 wires les than the nc21.
nc21 has a camshaft sensor.
xivlia wrote:i dont go fast on this bike so really do not need a rear brake.. /
vic-vtrvfr wrote:Ask xivlia for help, he's tackled just about every problem u could think of...