Honda RVF400/NC35

[acidhurt]

Originally posted by Ken@Mar 14 2004, 02:46 AM

u go back to that shop, they will change it back for u, but with something not well done and soon it will have probvlems and u go back, they will say, see lah tell u liao...

this is wat they say before i left the shop.. sigh.. now very headache.. btw, i noticed tat my headlight and signal light will glow when i rev.. is this normal? COs i dun think it used to glow before.. Thinking of going K&T to redo my rectifier wiring back to original..

 

one more qns, is it a norm for RVF when headlight not ON and u speed, it will overcharge the batt?

[Shay]

ok ok...this will be useful for all u RVF siaos out there!

 

remember....with great power comes GREAT COSTs and reasonable doubt of engine reliability issue. the article below is extracted from 400 GreyBike.com. it spells out all the things u can mod for yr NC in 4 stages...stage one been the DIY stuff and stage 4 been the "path of no return"...read on RVFians who are powermad!

 

"Greetings NC freaks!

 

 

 

This time I'm going to talk about tuning your grey import NC30 for more power and speed, so first we need to understand the baseline from which we are working.

 

 

 

Japanese legislation during the NC's production period required that 400cc bikes should produce a maximum of 59bhp and be speed restricted to 180Kph (112Mph). As you will all know by now, the speed limit is electronically imposed and can be overridden by fitting an M-Max or similar derestriction unit in series with the ignition "black box", under the seat hump. This does not make the engine produce any more power, it simply allows the bike to reach its true potential top speed of 125Mph or so. The NC30 engine unit was designed with the brake horsepower limit in mind, and so in standard road legal trim 59 BHP is the most that a healthy one will produce. This can be improved upon to some extent by modifications to inlet, exhaust and ignition systems to allow the engine to breathe and rev more freely, but you will always be bumping into the inherent limitations of a "designed for 59BHP + engine, and so extracting serious power increases will require the attentions of a professional tuner to carry out such internal work as porting, increasing compression ratio, changing cam profiles and fitting big bore kits. I will therefore approach the subject in two stages - the "bolt on/do it yourself" level, and the "call in the professionals and spend big money" stage.

 

 

 

DOING IT YOURSELF

 

 

 

1) Exhaust system - this is where we all start, 'cos let's face it, a standard NC does sound like a sewing machine, doesn't it? The cheapest and simplest option is to fit a "slip-on" replacement can. These are available in road legal or race types. Road versions are unlikely to show any significant performance increase, although they may sound a bit fruitier than standard. Race cans will improve performance, but are, of course, illegal for road use, so don't tell anyone I encouraged you! There is a relatively wide choice of race cans on the market - a £300 carbon fibre job won't perform any better than a £130 alloy one, it just depends on how much you value the pose factor. Because the collector pipes and silencer of the standard system are all one piece, you will have to saw off the silencer to fit a "slip-on" can. Some manufacturers supply an adapter to re-fit the standard can for M.O.T. purposes, but I would suggest that if you have an undamaged standard exhaust on your bike, you don't saw it up, 'cos they are scarce and valuable - get your local breaker to sell you one with a crunched silencer (plentiful and cheap) and use that to mount your race can on.

 

 

 

The second option is to fit a "half system", which uses the standard front pipes, but replaces the original collector and silencer assembly with something lighter and more efficient. As far as I know, no-one in the U.K. make such a system, but many Japanese after-market suppliers do, so lots of them come in on grey imports. I've seen at least four different versions; mostly they are all-stainless constructions, and are designed and fabricated to a standard which puts certain major British exhaust makers to shame. Shop around at grey importers and breakers and see what they have in stock - you might just buy yourself a bargain.

 

 

 

Note: SWONA now make a half "twin STack" system for the '30 and '35. See their details in the suppliers section.

 

 

 

The final option is to fit a full race system. The only one available in the UK is made by Micron. This replaces the entire standard exhaust and is a multi-sectional job with quick release, spring-retained joints. It is a 4 into 1 system with equal length headers (all others mentioned so far are asymmetrical 4 into 2 into 1 systems) and is therefore tuned to give optimum top end power, possibly at the expense of some mid-range. This system will give you the most peak RPM horsepower, and the more tuned your engine, the better it will work.

 

 

 

Drawbacks are:- a) You have to remove the fan assembly from behind the radiator and, b) The cost - nearly £800 new.

 

 

 

However, as I keep saying, shop around - I bought my Micron with a scratched can from the Motorcycle News classified ads. for £150.

 

 

 

2) Air Filter - the first thing to say is don't be tempted to remove or seriously modify the air filter box. The shape and volume of the box are tuned to work in harmony with the carbs for the best spread of power, and removing it will radically interfere with the carburation. Just fit a K&N filter element, which will give slightly freer airflow and also will never need to be replaced.. One small D.I.Y. which will help breathing is to re-direct the airflow into the airbox snout by cutting a window into the plate which extends forward from the bottom airbox moulding into the space behind the steering head.

 

 

 

If you look at your bike from the front, you will see a small plastic airscoop just above the top radiator. This directs air into the "vee" of the motor to keep the carbs cool. The plate on the front of the airbox forms the top wall of this airduct, and you will see that, if you cut it away between the moulded ribs, then the airbox intake will breathe clean cool air from under the fairing nose instead of hot stagnant stuff from beneath the tank. Pop rivet some gauze over the aperture that you've made in order to keep the flies out. It's nothing like a proper "ram air" system, but its an improvement.

 

 

 

Since the original draft of this article, I have further improved the airflow on my own bike by cutting the front completely off the bottom airbox moulding in line with the frame cross tube, removing the rubber ‘Trunk’ from the front of the top airbox moulding and enlarging the resulting aperture to approximately 100mmx65mm – slightly more intake noise but seems to work well.

 

 

 

3) Carburettors - Now that everything is flowing more freely, the carbs will need rejetting to suit. Without getting too technical, there are basically three overlapping phases in carburettor operation. The pilot jets and airscrews control tickover and initial pickup, the needles and needle jets cover the mid-range and the main jets take over when the throttle is fully open.

 

 

 

The very least that you will need to do is get the main jets right. An alternative set of needles will improve mid-range, and there is a carb slide modification which will improve the speed of pick-up.

 

 

 

As I mentioned in the last magazine, early (RK) Model NC30s have 110 main jets, which need to be changed for 115 front/118 rear as fitted to later models, or 118F/120R if you are using a race pipe. This is a rule of thumb guide to sizes, which you can double check by having your bike run on a rolling road and checking exhaust emissions with the CO meter.

 

 

 

Mid-range carburetion can be improved by changing the carb needles, this will fill in the noticeable flat spot which is present around 5 - 7,000RPM on most NCs. I have personally tried two different carb needle kits (both of which come complete with main jets). The first was the American-made "Factory" kit, and much as I hate to slag off anyone's products, I have to say that, fitted as per instructions, it made practically no difference to the power curve, but did put fuel consumption up from high 30s to low 20s of miles per gallon. Putting that one down to experience, I subsequently tried the kit now marketed by FI International. This uses dynojet main jets and their own custom-made needles, and it works just fine, filling in the mid-range and improving peak power by 5BHP with a race exhaust. It should be noted that Dynojet main jets as used here are, because of their better flow characteristics, effectively one size larger than standard Keihin jets, i.e. Dynojet 118s are equivalent to standard 120s. Pilot jets will not need changing, just make sure that the pilot air screw settings are as per the Workshop Manual or carb. kit instructions (usually around 2 ¼ turns out from fully seated).

 

 

 

The last carburettor mod is to reduce the degree of damping on the slides to enable them to rise more quickly when the throttle is opened. This has no effect on power, just improving throttle response, and is achieved by increasing the size of the air bleed holes which you will find in the bottom of the carb slides, off to one side the needle. Remove the slide from the carb as per the instructions in your Manual and extract the needle from the slide. Carefully drill out the air hole from its standard 2mm to 2.5mm, blow out any swarf and reassemble the carbs.

 

 

 

4) Ignition – At this level of tuning, a derestrictor box (for Grey Imports), and a set of colder grade plugs will be sufficient.

 

 

 

With regard to derestrictors, I need to correct some of my own misunderstandings as previously posted here!

 

 

 

The small HRC box which plugs in series with the standard ignition unit under the seat is in fact no more than a higher quality and more expensive version of an M-Max or any other derestrictor and fulfils exactly the same function (I’ve run them back to back on the dyno to confirm this).

 

 

 

The full race HRC ignition with modified advance curve and higher rev limit is a larger unit which completely replaces the standard black box and also requires a special race wiring harness. Both are still available, priced at about £90 and £350 respectively.

 

 

 

Plugs should be changed from the standard ER9EH to ER10EH if you are an habitual thrasher or track day artist.

 

 

 

If anyone out there needs a derestrictor, I have manufactured a batch which I can supply for a very reasonable price – phone me for details or check out the workshop section for future articles.

 

 

 

5) Clutch – A few extra horsepower may well overwhelm your standard clutch if it’s getting a bit tired, so a rebuild and ‘Beef Up’ would be wise.

 

 

 

Strip the clutch (Special peg spanner needed for the centre nut). Check the metal plates for flatness on an engineers surface plate and replace if warped. Replace the friction plates if they are worn below (or even close to), the service limit of 2.8mm thick. EBC friction plates, available at most dealers for around £40 a set work very well in my experience and are less than half the price of genuine Honda parts.

 

 

 

Uprated clutch springs are not readily available because the NC30 uses diaphragm, rather than conventional coil type springs. However, a quick and effective fix involves adding a fourth spring to the standard stack of three. This will prevent clutch slip at the expense of a slightly stronger lever action.

 

 

 

Honda only sell springs in sets of three, but I will supply singles if required.

 

 

 

That's about it as far as D.I.Y. tuning goes, but if your engine is in good condition, it should now be giving a good spread of power with no flat spots, peaking at 62- 63 BHP and revving out to 14,000 RPM.

 

 

 

GETTING SERIOUS

 

 

 

Professional tuning is a highly precise, labour intensive job, and as such is going to cost a not inconsiderable amount of money, so, before you go down this road stop and think about the fact that the cost of a cylinder head porting job, when added to the resale value of your NC would easily buy you a late model CBR600 or similar, producing 100 BHP in standard trim. Having pondered on that, if you love your '30 enough to proceed, here's a rough idea of what you'll get and what it will cost you. I've based this on information kindly provided by Stan Stephens and by T.T.S., both of whom have reputations for good quality work and offer "staged" tuning packages.

 

 

 

Stage 1

 

 

 

Carb. modifications and race can - same as you can do at home, but done by the tuner and set up on his dyno - cost around £90 for the carb kit, £150 - 300 for the can plus maybe £50 for the setting up and dyno time. Result - 64BHP and improved mid-range.

 

 

 

Stage 2

 

 

 

Cylinder heads ported and gas flowed, valve seats recut, combustion chambers modified to increase compression ratio - cost £500 - 600 if you strip your own engine and just send the tuner your heads - add anything up to another £500 if you want to take the bike in and have it done for you. Result - similar power curve, but more of it, peaking at possibly 66 - 68BHP.

 

 

 

Stage 3

 

 

 

Camshafts reground to a more "racing" profile - cost £350 - 400 exchange, plus a small charge for fitting (or maybe fitted free if done at the same time as a Stage 2 package). Result - more top end power. Maximum BHP now perhaps 68 - 70, but produced at 13,500 RPM instead of 12,000, enabling the bike to be geared down for better acceleration with no top speed loss.

 

 

 

Stage 4

 

 

 

444cc big bore kit - cost £470 for pistons plus maybe £200 for reboring work and the usual £400 - 5-- to rebuild the engine. Result - more power and torque throughout the rev range, peaking at 75 BHP if you're lucky.

 

 

 

Before leaving the subject, I have to mention that the ultimate engine job is a full tune and blueprint done by Honda V guru, Tony Scott, engine builder to many top race teams including Honda G.B. The following list shows what is involved, and the price of £1,600 plus parts hardly reflects the time and care taken. "Plus parts" in this context would ideally mean the HRC race kit of cams, carbs, etc., which would probably have to be specially imported from Japan, and cost nearly the price of another NC30! Having said that, what you will end up with is the sweetest, smoothest running and most powerful NC engine that money can buy, and bullet proof reliability as well. Master craftsmanship has never been cheap.

 

 

 

So, to summarise - £2 - 300 wisely spent can buy you a noticeable performance increase, major power gains will cost you big money, and next time someone tells you that his bog stock NC30 with a loud exhaust is making 70BHP, you will absolutely, categorically know he's bullshitting!!"

 

 

 

Rick Oliver

[Guest KeiHin99]

hihi guys, me gonna sell off my RVF cause license gonna get revoke soon, so any of you guys have frens who are thinking of buying, pls let me know... mine is a FM plate, though it is not of the best condition i would say, but to me its still a decent RVF. Pls do not ask me all the technical aspects of it cause me not a technical guy, i belong to those who just buy and ride only.

 

Original paintwork, FM7***, $6.2k

 

Faster, faster, cause me gonna push back to motorshop somewhere this month.

Push back to shop, they also take in abt 5.3k. If got ppl buy from me, i can earn another 900 bucks.

 

I live in Hougang, wanna view bike can make appt, after 6pm. Buyer must have full cash settlement, cause bikeshop cannot reloan.

 

Okok, thats about all, thanks for those who take time to read.

 

[Guest KeiHin99]

opps, ya, forgot to leave contact... hehe 97617406, Philip here!

[vroomvroom]

sorry abt yesterday for having to leave suddenly ar...

 

but it was a laughing good time .. esp when benson and terence starts to eat tt 'cheezy' 'hotdog' tt 'spew' ..haha

 

my headlights playing tricks again .. jus now on bike no headlight .. on off the switch still no light .. then press high beam got light .. press back low beam , light turn back on ... hope it dun fail me ..dun wanna waste time down to bike shop again

[benson]

Originally posted by vroomvroom@Mar 16 2004, 12:12 AM

sorry abt yesterday for having to leave suddenly ar...

 

but it was a laughing good time .. esp when benson and terence starts to eat tt 'cheezy' 'hotdog' tt 'spew' ..haha

 

my headlights playing tricks again .. jus now on bike no headlight .. on off the switch still no light .. then press high beam got light .. press back low beam , light turn back on ... hope it dun fail me ..dun wanna waste time down to bike shop again

Ur rect n batt might be ok n the prob cosin all this might be ur starter switch like wad mine did to me last time. aft startin ur bike, try tappin instead pf pressin the button u use to start the bike. if the lights on or just flick, den its the switch prob. also check ur fuse. rvf headlight fuse always break. take out ur pillon seat, open the fuse box n pull out the light's fuse n see if its broken.

[jungleboy111]

benson : JB makan on 21st? I can go on 21st.....

[benson]

RVF Outing (LATEST)

Date : 21/3/04, Sunday

Time : TBA

Venue : Malaysia-JB-Da Mah Hua Yuan a.k.a Big Horse Garden

(meetup ard WL or in JB or anywhere convenient)

 

Riders:

 

1) benson - 94568245/90992983

2) jungleboy - 97907140

 

Pending:

 

A trip for tasty, delicious, cheap, nice, CRABS, PRAWNS, STINGRAYS, DELICACIES, WILD "FOOD".......

 

[jungleboy111]

[Shay]

hey jungle....

 

wonder if FJT sells loose spare parts as weird as...say..... The 3 metal brackets of the pillion seat??? if u should go down again..can u help me ask??

 

i wana buy them becoz im sick of transfering the screws and brackets everytime i transform between a singleseater and the pillion seat. damn bloody troublesome.

 

thanx man!

[jungleboy111]

Originally posted by Shay@Mar 16 2004, 06:59 PM

hey jungle....

 

wonder if FJT sells loose spare parts as weird as...say..... The 3 metal brackets of the pillion seat??? if u should go down again..can u help me ask??

 

i wana buy them becoz im sick of transfering the screws and brackets everytime i transform between a singleseater and the pillion seat. damn bloody troublesome.

 

thanx man!

You mean the metal pieces on the bottom of the pillion seat that locks on to the bike rite?

 

Ok... I'll ask for you when I have the chance to go to FJT.

 

Anyway, whatever parts you need, you can order from Japan from Devin... the guy i ordered my engine casing from. He can get any OEM parts you need.

[Shay]

Originally posted by jungleboy111@Mar 16 2004, 09:15 PM

You mean the metal pieces on the bottom of the pillion seat that locks on to the bike rite?

 

Ok... I'll ask for you when I have the chance to go to FJT.

 

Anyway, whatever parts you need, you can order from Japan from Devin... the guy i ordered my engine casing from. He can get any OEM parts you need.

oh yea! the latching on metal brackets .all 3 of them... the two metal hooks at the front and the U shape metal bracket that locks to the latch.

 

BTW...whoz Devin? from which shop one? or is he a distributor?

 

odering this all str from japan ah? hmmm.....i just hope it will not come to that lor..imagine paying handling/txport fee for 3 miserable bracks...

 

anyhoo....the msia shootout....ONZ u all LA! but must n0t be too early la....might have to work .

[joshy]

Originally posted by benson@Mar 16 2004, 03:25 PM

RVF Outing (LATEST)

Date : 21/3/04, Sunday

Time : TBA

Venue : Malaysia-JB-Da Mah Hua Yuan a.k.a Big Horse Garden

(meetup ard WL or in JB or anywhere convenient)

 

Riders:

 

1) benson - 94568245/90992983

2) jungleboy - 97907140

 

Pending:

 

A trip for tasty, delicious, cheap, nice, CRABS, PRAWNS, STINGRAYS, DELICACIES, WILD "FOOD".......

 

da mah hua yuan = taman sentosa.

not big house garden

 

[jungleboy111]

Originally posted by Shay@Mar 17 2004, 01:47 AM

oh yea! the latching on metal brackets .all 3 of them... the two metal hooks at the front and the U shape metal bracket that locks to the latch.

 

BTW...whoz Devin? from which shop one? or is he a distributor?

 

odering this all str from japan ah? hmmm.....i just hope it will not come to that lor..imagine paying handling/txport fee for 3 miserable bracks...

 

anyhoo....the msia shootout....ONZ u all LA! but must n0t be too early la....might have to work .

He stays in Japan and has dealings with the Honda manufacturers. He does ebay stuff as well. Of coz his shop is in Japan.

 

Alot of times, he waives the shipping charges or gives discounts... Best thing is he is very transparent. If you need to order anything, just tell him to work out all the costs involved and you can decide if you want to order from him anot.

[benson]

RVF Outing (LATEST)

Date : 21/3/04, Sunday

Time : 1700-1730

Venue : Malaysia-JB-Da Mah Hua Yuan a.k.a Big Horse Garden

(meetup ard WL or in JB or anywhere convenient)

 

Riders:

 

1) benson - 94568245/90992983

2) jungleboy - 97907140

3) shay

 

Pending:

 

A trip for tasty, delicious, cheap, nice, CRABS, PRAWNS, STINGRAYS, DELICACIES, WILD "FOOD".......

 

 

[Shay]

Originally posted by benson@Mar 17 2004, 03:25 PM

RVF Outing (LATEST)

Date : 21/3/04, Sunday

Time : 1700-1730

Venue : Malaysia-JB-Da Mah Hua Yuan a.k.a Big Horse Garden

(meetup ard WL or in JB or anywhere convenient)

 

Riders:

 

1) benson - 94568245/90992983

2) jungleboy - 97907140

3) shay

 

Pending:

 

A trip for tasty, delicious, cheap, nice, CRABS, PRAWNS, STINGRAYS, DELICACIES, WILD "FOOD".......

 

 

yo.... if we go jb makan....safe anot ah???

a gang of RVFs in the midst of notorius JB?? danger anot ah..heard so many stories leh...

 

that oso means its very short distance only right?

cannot have a 'shootout' liao!

 

haha!

 

[usmonkey]

Brothers,

 

No worry abt the JB trip la. I go down every sunday, sometimes alone to go Pasir Gudang. No biggie man.

 

Anyway, im heading down track again this Sunday. Anyone care to join in da fun?

 

Hey BUZZBEAM,

 

Are you still going down on Sat? Jungleboy is interested going on Sunday with me.

Confirm pls.

 

Victor, ,

I tried using your chisle and Hammer technique to adjust the preload of da rear shock. It sorta worked, but it left lots of "scars" on the knobs. Outch. There must be a legit way of doing it man.

[Ken]

acidhurt, think u better go do up ur bike asap lah, no point thinking wanna do or not here.

 

i dun really like nike products, but i like their slogan.

 

Just Do It.

[benson]

guys! pls add on the the list asap.... onli 3 days left.......

[jungleboy111]

Henry: here are the links

 

Tyga Rearsets

http://www.tygaperformance.com/racingsteps.htm

 

WR's Battle Step

http://www.g-t.co.jp/parts/P_086.htm

 

Raynor Rearsets

http://www.rearsets.co.uk/

 

TCM Rearsets

http://www.akhara.com/nc30/tcmrearsets/

[BeowulF]

Originally posted by usmonkey@Mar 17 2004, 09:39 PM

I tried using your chisle and Hammer technique to adjust the preload of da rear shock. It sorta worked, but it left lots of "scars" on the knobs. Outch. There must be a legit way of doing it man.

Yo, USMonkey,

 

Get a adjustable C-spanner to do the preload.

[jungleboy111]

Whos interested in racing suit.... makes me saliavate!!

http://www.bg-performance.com/arlenness/leather.htm#

 

What about gloves?

http://www.bg-performance.com/arlenness/images/source/G880.gif

 

Cool boots!

http://www.oxtar.com/oxtar/img/catalogo/prodotti/54_big.jpg

 

 

Anymore pple here wanna go down track? Or wanna order track gear? Looking for more RVF kakis to go track.... (I've not been to track b4 yet)

[bikemania]

I ON

 

I also wan to see how i can fare on the track but can wait for a few mths first???

Cos i a bit leong nw. wait for me to buy a little bit of acessoriess every mth can??

 

I LOVE TRACK!!!!

[jungleboy111]

Originally posted by bikemania@Mar 19 2004, 05:26 PM

I ON

 

I also wan to see how i can fare on the track but can wait for a few mths first???

Cos i a bit leong nw. wait for me to buy a little bit of acessoriess every mth can??

 

I LOVE TRACK!!!!

Cool... coz usmonkey n buzzbeam oso go down track one... we can join them..

 

The racing gear can slowly lah... i oso no money... gonna use touring jacket, jeans n army boots for the time being...

 

Just a little taste of how much it can set in...

For example the stuff I showed above...

The suit is between $1.2k-$1.8k, the boots ard $400, the gloves I dunno how much...

Will need ard $2k to get those stuff.... I'll have to wait sometime on these things...

Anyway, me n usmonkey going track this wkend...u wanna join us?

[bikemania]

Originally posted by jungleboy111@Mar 19 2004, 05:42 PM

Cool... coz usmonkey n buzzbeam oso go down track one... we can join them..

 

The racing gear can slowly lah... i oso no money... gonna use touring jacket, jeans n army boots for the time being...

 

Just a little taste of how much it can set in...

For example the stuff I showed above...

The suit is between $1.2k-$1.8k, the boots ard $400, the gloves I dunno how much...

Will need ard $2k to get those stuff.... I'll have to wait sometime on these things...

Anyway, me n usmonkey going track this wkend...u wanna join us?

Wat time u all going down??? I dun know whether my jacket n jeans can anot??

I meet u on friday to take from u the service manual book and let u see my jeans n jacket first. I scare later suay suay buang, i can go sell mei zhen xiang already Likely to wear army boots loh, Can????