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vfr400r nc21 performance question

Posted: Sun Jun 20, 2010 10:52 pm
by smudge72
Hi,

I've owned my vfr for a couple of weeks or so and I'm a little disappointed with the performance.
I understand these bikes should do 0-60 in 4 or 5 seconds and 60mph in first gear, I'm not getting anywhere near that, it will do about 40mph in first at most.
Engine revs are about 8000 for 80mph in sixth gear.

I'm wondering if my vfr is a tad ill?

Thanks,
Matt.

Re: vfr400r nc21 performance question

Posted: Mon Jun 21, 2010 9:07 am
by porndoguk
im not expert on the VFR yet only had it a week but it sounds like yours is very ill! i took mine out for its maiden voyage yesterday and was quite shocked with its power which i thought would be considerably less than it is.

not sure of the condition of your carbs but maybe rejetting cleaning etc would improve that 0-60 time a little

mine does 60 in first all right but id rather not hit those speeds in first gear

8k in 4 will be giving me around the 100+ mark

Re: vfr400r nc21 performance question

Posted: Mon Jun 21, 2010 12:11 pm
by Neosophist
rickyb_dj wrote:im not expert on the VFR yet only had it a week but it sounds like yours is very ill! i took mine out for its maiden voyage yesterday and was quite shocked with its power which i thought would be considerably less than it is.

not sure of the condition of your carbs but maybe rejetting cleaning etc would improve that 0-60 time a little

mine does 60 in first all right but id rather not hit those speeds in first gear

8k in 4 will be giving me around the 100+ mark
NC21 has different gearing than the NC30..

Were you out on the Black Country Route? I passed an NC30 yesterday or Saturday (can't remember which...) Don't see many of them round by me.

As for the NC21 Does it rev to the red line in first gear? If so then its fine... if your doing max RPM then your going as fast as you can in that particular gear.

Only thing would be clutch slipping, but you'd be revving a lot higher than your travelling (pretty obvious to see)

The NC30 has a really long first gear, differnet to the NC2x.'s

Re: vfr400r nc21 performance question

Posted: Mon Jun 21, 2010 9:32 pm
by smudge72
hmm...I guess it could be a slipping clutch. The previous owner used car oil, could that cause it?

If any one out there with an nc21 could tell me what revs at what speed and which gear, that would put my mind at rest. It pretty much seems to be, in sixth gear that 1000 rev=10 miles per hour, so 70mph is 7000 and 90mph is 9000 etc.

Thanks!

Re: vfr400r nc21 performance question

Posted: Mon Jun 21, 2010 10:14 pm
by Old Painless
Car oil will probably cause a slipping clutch. It has friction modifiers in it as cars run dry clutches.

Drop the oil, flush with new stuff then drop that and replace the oil and filter. Should see you right.

Re: vfr400r nc21 performance question

Posted: Mon Jun 21, 2010 11:00 pm
by Neosophist
If your revs go up but the speed doesn't the clutch is slipping, as it gets worse you'll be able to red-line it in gear without the bike going anywhere. Put the bike in gear with the front brake on and loose the clutch out, if the engine stalls the clutch is more than likely ok.

It's probably becuase it's an NC21 and not an NC30, it doesn't have a tall first gear, it will probably do, 35-40 in 1st.

Disappointed with the performance? What are you comparing the performance to? It's a 25 year old 399cc bike.

Put it in gear and and ride, if you can get to the red-line while your speed goes up accordingly your clutch and bike are fine.

80mph @ 8000rpm in 6th sounds about right.

Time it from 0-100km/h. It will also depend on your riding style, clutch changing ability etc.

Trade it in for an old CBR600F if you want something of a similar price but faster / more reliable

Re: vfr400r nc21 performance question

Posted: Wed Jun 23, 2010 1:58 am
by Morespeedvicar
Hi,
just wondered if its been restricted or something, maybe worth taking carbs off and checking theres no washers in the inlet manifolds, and cleaning the carbs out while your in there.
Cheers
Ian

Re: vfr400r nc21 performance question

Posted: Wed Jun 23, 2010 10:58 pm
by smudge72
Hello all,

Well, I guess its fine then, its just that my last bike was a gsx600f and was much faster. I had a bit of a race against a gsxf a few days back, he left me for dead on the straights but couldnt keep up on the twisty bits.
I really like the handling of this bike, not only does it react fast to input and can change line really well even when leant right over, its also very stable and secure, hitting bumps and holes while cornering cause no 'hang on and pray' moments I've had on other bikes. It just has a bit of a twitch and keeps on line.

Thanks!

Matt.