New owner, pulling down RVF for the first time

[Drunkn Munky]

If its a road bike leave the intake/carbs stock and upjet, tweek the needle height. Hrc carbs don't hurt rideability, I have the full kit on mine Inc airbox etc and low down/midrange is actually pretty good it's just it uses no filter so if you do a reasonable amount of road riding its not a good idea.

[CMSMJ1]

road bike - keep it standard - simple as that.

[antiengineered]

More and more with the mixed opinions

Why don't you recommend the HRC kit Drunkn Munky? Surely it could be carried out with an air filter in place.

[skinnydog0_0]

More and more with the mixed opinions

Why don't you recommend the HRC kit Drunkn Munky? Surely it could be carried out with an air filter in place.

The idea of the HRC NC30 kit it to have maximum unrestriced (NOT Ramair) air flow to the carbs. If you use a filter you are starting to restrict the flow.
The HRC kit is only really any benefit when you are high in the rev range - so as DM says, the possible damage from road grime for the small benefit is really not worth it.
As DM and CMSMJ1 have said just upjet and keep it standard.

[antiengineered]

That's crazy that an air filter could be enough to upset the balance. How's that for crappy air box design.

Sounds like keeping it simple is the approach.

[Drunkn Munky]

eh? an air filter on any bike would be enough to upset the jetting from using a open carb setup, theres less air getting through and theres no way around that.

[antiengineered]

A good air filter set up will out flow the CFM capabilities of any engine, and a well set up intake will evenly distribute that air. Then tune to suit.

Maybe I'm spending too much time around modern cars

[Drunkn Munky]

That maybe so but the point here is the HRC kit is designed to work without a filter, plus were working with 20 year old technology here so i guess airbox/intake design isnt the best.

[Neosophist]

A good air filter set up will out flow the CFM capabilities of any engine, and a well set up intake will evenly distribute that air. Then tune to suit.

Maybe I'm spending too much time around modern cars

Guys I need some advice on what carbie parts will be best for me. I am going to get it professionally dynotuned. It is a road ridden bike, no racing. Standard headers. I am not looking to go all-the-way with the power mods, just pull the bike apart once, clean it up, fit some trick bits if they won't have any draw backs, sync the ITB's, get it tuned and enjoy it. No more tearing down every couple of weeks to tweak that and add this; just ride it.

I am interested in the HRC kit, but am hearing conflicting reports on rideability and some even of partially reverting back to stock. Some of these posts however state that the owner hasn't had the bike tuned properly and wonders why it doesn't run right... so they obviously have no idea what they're doing. It is the same story with air box modification - hit and miss depending on who you ask.

What would you recommend? I more or less want the most out of the bike without impacting overall drive ability.

Right first of all.

There are not really and power-mods for this type of old greybike without getting really involved. They are designed and setup really well to deliver the most power from the engine and a smooth road-going form, especilaly the NC35.

All you need to get the most out of the bike is a free-flowing exhaust (a half system which utilises the existing front down-pipes and to up the jetting a little bit, leave everything else well alone and you should get a bike around 60hp that delievers a lovely smooth linear power-curve.

These bikes are already at the high-end of the old 400cc development chain coming from a line of race-engines and are quite strung-out as it is. Unlike a lot of engines, especially car engines where a little bit of fettling is easy to coax more power beucase the engine is so down-tuned at stock level, all that doesn't really apply to this.

Also many cars use some kind of generic engine that is shoved in many chassis and is quite flexible, this whole package was designed to work together.

"I am interested in the HRC kit, but am hearing conflicting reports on rideability"

Couple of things here, if you want a road-bike forget it.

Secondly, it is a kit, consisting of a lot of parts (the full kit virtually rebuilds the entire engine) and most of it is long unavabile and whatever crops up goes for mega mega mega bucks, and since it is a kit it is designed to work with everything.

Finally its the Honda Racing Kit is exactly that, a kit to build a 400 class race-bike, i.e. open carbs, huge jets, crap fuel economy 4000rpm idle speed, all power at nearly max revs.

People do like to rave about the old rvf and they are a pleasure to ride, they have a good range of usable power and you can use most of it a lot of the time unlike modern bikes which by comparission are scary angry and uncivilised but truth be told if you want more power get a newer bike.

A modern cbr600rr is lighter, faster, handles better and has nearly twice the power of an rvf, everyone has heard the story that in the bends you will loose any bike compared to a vfr/rvf but its more and more rose-tinted glasses, maybe an old cbr750 or something then yes but 25 years is a long time for things to change, just as ive kept up with guys on zx10rs due to their ability ive also had my ass handed to me on occasion from guys on power cruisers.

like for like riding ability a new 600 will eat an old rvf/vfr.

Might not have the same character and looksthough, which is afterall why so many still ride them. The most enjoyable rides I have on bike are all sub 50hp bikes.

[Drunkn Munky]

That just about sums it up except, the rvf doesn't have a hrc engine kit unlike the VFR and therefore the rvf hrc carb is designed to work with stock engine internals although I dare say the heads will have been fettled.