VFR400R vs. CBR250RR

[Drunkn Munky]

There between the carbs and inlet, remove the carbs and if there's a metal disc in the inlet rubbers take them out and it's happy days. Drop a tooth on the front sprocket and it 'll be bye bye cbr

[Cammo]

Omg Munkey, I hope your right. I had heard that it could possibly be restricted but nobody seemed to know.
It is supposed to be a learner approved 400 and i figured that surely it would be restricted but didnt know for sure.
I'm gonna check out my carbys asap now. Also Im a bit of a newbee on bikes, where exaclty will I find these
restricting rubbers? In or underneath the carbys? Cheers :)

There won't be any restrictors in the carbs, that's a UK (non factroy) licensing thing. Oz bikes won't have them as they all come from Japan.

The only restriction they have is a 180 km/h limiter which can easily be bypassed.

Do as Munky says and get a 14t front sprocket on it and will be a rocket.

All the carb mods you mentioned also help quite a bit. Not difficult to do yourself by any means, just takes a while the first time you get stuck into it. All parts you need are easily available.

[CMSMJ1]

If it was sat for a year then yes there will be crap in't carbs - get them cleaned too...that will help.

[DanHam]

In relation to slipping the clutch I do it all the time on my 125 well you have to for a fast getaway.

Is it safe to do it on the vfr?

[fastdruid]

Depends how aggressive you are with it, I'm pretty sure despite the high gearing and low power you could still loop it if you were very ham fisted.

Druid

[Wilson]

G'day. I ride both these bikes (we don't have LAMS in WA, so the 250 is my daily), and I'll confirm that the 250 is the easier to launch. Biasing factors could be that my 250 is +2 on the rear for better acceleration, and the fact that I've got more km under my belt on it... but when you consider the CBR is geared for 65km/h in first with 45hp, and the VFR will do about 110km/h in first with 60hp, you can see that you're going to have to be a lot better with the clutch to get a good launch out of the VFR. Once you're moving, though, the extra pull of the 400 is noticable.

I think my clutch lever needs adjusting or summat... because I hit a certain point when taking off when it'll bite all in one go and bog me down, and I've only ever been through that zone slow enough once.

[ls1vzssz]

Well, thanks greatly to Dataracer. Following his D.I.Y carby re-jet guide
I did all the work myself without spending a packet. Now the 250 Ninja and
250 Cbr RR don't stand a chance against the almighty 400. Even if I don't get
a great start off the line the power of the VFR is easily enough to catch and pass
my 250 mates. It's not all about speed I know, however it is very satisfying that
now my 400 goes like it should and does the job I wanted it for in the first place.

Thanks again to all those who helped

[muay_thai_dan]

ok guys i have a ridiculously newb question....

Thanks for all the replies guys. Im gonna go out and get some more practise on my starts for sure. I might
even think about changing the gearing as some of you have suggested, sounds like a cheap mod. I live in
South Australia and I'm looking for a bike shop now who can do some tuning on my carbs as I've read the
flatspot around 5000rpm can be fixed by going up a jet size, lifting the needle 0.5mm and also drilling out the slide
up from 2.0mm to 2.5mm.

what are jets?
what is lifting the needle?
and what is drilling the slide?

i googled it, and couldnt find info. for "jets" i just get results for airplanes and jet engines and what not.

thanks a lot, and sorry if its really basic stuff, im justn ot that mechanic savy but love bikes.

[ls1vzssz]

I was referring to work that I carried out on the carbies. Just go check out
Dataracers sticky on D.I.Y carby re-jet in the V4 workshop section. It will
explain all that you need to know.

[superlite]

Good to see you've saved the little V4s face against those pesky 250s!

Result for the team!