Got the bikes, got the knowledge, got the T-shirt
Improve Honda’s NC30 Rick Oliver is a self-taught Honda V4 expert and the UK’s authority on the VFR400R NC30. He’s spent 20 years improving his own 400cc V4 – this is his hard-won wisdom Words: BENJAMIN LINDLEY. Photography: Matt Hull
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ick Oliver first bought an NC30 in 1992. Twenty years on and his improvements, conversions and replacement parts cover every aspect of the bike. He makes few claims to being the originator of his workarounds and doesn’t seem to have a financial motivation for producing them, emphasising instead that they are the result of an international community effort to make this fantastic motorcycle even better. Despite this, he has created a comprehensive stocklist, even selling V4 T-shirts to fans of Honda’s cult sportsbikes. The official NC30 imports to the UK were dearer than CBR600s of the day. It was a blatant attempt by Honda to milk the RC30’s image by selling the 400 replica at twice its Japanese market price. Given that, it’s no wonder grey imports became so popular. I think the UK additions – an oil cooler, different mirrors, indicators and larger regulator/ rectifier – were simply to give you the perception that you were getting more for your money.
bore kit, which adds muscle throughout the rev range. Conventional tuning, such as race cams and high-compression pistons, tends to lift only the top end of the curve. On the road, the added midrange a big bore kit gives is worth much more than extra horsepower high up the revs. The JE kit is a good product, but their pistons are heavier than they should ideally be, so be sure to set the rev limiter down by a thousand revs or so in the interests of crankshaft life. VFR engines are pretty much bulletproof as long as they’re serviced at least once a year, ridden with respect and given regular changes of quality semi-synthetic oil. But watch out: most semi-synthetic oil today is better described as synthetic fortified. I use Morris Super Sport 4 and change it every year or 4000 miles. Avoid fully synthetic oils – EBC clutches have been fitted to most NCs by now, and they don’t like it.
tools of my trade
The RC45 is more a spiritual successor to the RC30 than its direct descendant. The 1994 RC45 is fuel-injected and has a more revvy boreto-stroke ratio. In contrast, the NC35 is a much closer relative of the NC30, but it was only available in Japan and was limited to 53bhp by Japanese law. Japanese NC30s and 35s were sold with a restricted top speed of 180kph. However, UK-spec NC30s do not have this restriction. The M-Max and HRC derestricting boxes for Japanese NC30 and NC35 are way overpriced for the simple function they perform. I do a fix that takes ten minutes to fit and costs £6. It’s a resistor that substitutes for a speed sensor in the speedo, fooling the ignition unit that the bike is always doing less than 180kph. HRC ignition boxes are hard to find, and when one comes on the market it costs upwards of £300. I’ve worked with the Czech company Ignitech on developing a more versatile ignition system to replace the Honda original and HRC versions. The Ignitech programmable ignition box is a very reliable piece of kit with lots of useful tricks up its sleeve. I can supply it with the original or HRC maps, or you can build your own ignition curve as the bike is running on a dyno. The standard NC30 version is £140, and it helps to fill in the notorious dip in power at about 5000rpm. I still have the same NC30 I bought back in ’92 – I’ve incrementally improved it over the last 20 years. The most noticeable upgrade is the JE big
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Carburettor tools
The blue one is a No.2 Phillips that undoes the clips that hold carbs onto the engine. The orange 5mm flathead fits the pilot screws. The carb sync tool completes the set.
Fork seal drifts
These milled cylinders seat the fork seals well, and avoid chipping the inside of the fork with a hammer and punch solution.
Multimeter
A simple multimeter that reads amps and ohms is indispensable for keeping an eye on the NC30’s electrical health.
The lower radiator can get clogged up with dirt from the road. Soaking it in detergent and blowing compressed air through cleans off some crud, but 20-year-old radiators are often beyond salvation. I sell quality replacements that have 50% thicker cores and are 40% more efficient than clean originals. They cost £300 and it’s a simple drop-in. The Achilles’ heel of the NC30 is its regulator/ rectifier. It’s no bigger than a matchbox but it has to dissipate a lot of heat. Failure can cause a cascading fault that could fry your battery and your alternator if not discovered in time. Typical symptoms include short-term loss of battery charge, and an artificial lowering of the rev limit caused by the battery’s inability to provide enough energy to spark at high revs. Visual checks can serve as an early warning of an impending failure. Try to separate the connectors in the system – the three-pin block where the alternator plugs into the wiring loom, and the five-pin connector plug on the reg/rec unit. If the system has failed, one or both connectors are likely to be burnt or melted. Using a multimeter to do voltage checks of the battery and resistance checks of the alternator wiring can provide a more specific analysis of the problem. I can supply good quality, British-made reg/rec replacements for £70. Replacing the alternator with the stator and rotor from a Suzuki GSX-R1000 K5-K7 will help the engine spin up more quickly. At 600 grams, the GSX-R’s rotor is only one third the weight of the original, a saving of 1.2kg. The standard alternator is reliable enough; this conversion is to reduce the weight of the flywheel, letting the engine pick up quicker.
Ashes to ashes, dogs to dogs: the remains of Rick’s first gearbox
Rick’s new gears (right) are tougher 00
front wheel was the same as on the NC30, so cosmetically the new rear worked well. To get it to fit, my friend Nick Townshend and I had to remove the drive pins from the axle, fit VFR studs at a slightly larger pin circle diameter and make a slight modification to the nose of the hub to get it to seat well in the middle of the 750’s wheel. These mods lower the rear ride height by just 6-8mm. I now sell these conversion kits for £125. They include spacers that move the run of the chain 5mm to accommodate the slightly bigger tyre. I like to run Pirelli Diablo Corsas 120/60 17 and 160/60 17 on my NC30, but if I had to choose an 18” tyre, it’d be the Bridgestone BT-090.
Big Brothers are watching: two RC30s oversee Rick’s work
The weakest point in the NC gearbox is the sliding countershaft sixth gear. Under the extra stress of a tuned engine, the dogs twist off the wall of the selector fork channel – and the gearbox goes off like a hand grenade. Mine certainly did. Gear maker Ellis Moore and I have come up with a replacement gear that is made out of better steel, is more deeply casehardened, and has a thicker outside wall on the selector fork channel. Initially we only produced C6 gears, but we’ve since made replacements for all the sliding gears. They are currently undergoing thorough track testing in Californian Mike Norman’s 90bhp race NC30s. As standard, NC30 forks have multi-rate (progressive) springs. The spring’s initial rate is very soft, which results in a loss of about an inch of suspension movement just holding up the bike. Along with preload spacers, decent oil and an air gap gauge, my conversion uses slightly stronger straight-rate springs that cancel out that initial sag. I can also supply Race Tech revalving kits, either as a DIY kit or readymade to people’s own spec. Many people tell me the £85 spring conversion has transformed their bike. Both the RCs’ and NCs’ chassis were set up quite conservatively, and both benefit from a rear jack-up kit to raise the ride height by 20-30mm. This improves the steering geometry and cornering clearance. Buying a new, purpose-built rear shock is probably the biggest chunk of money you’ll throw at your bike, but it’ll be the best money, too. I supply Nitron and Öhlins shocks from £355 to £850. Back when I did a lot of trackdays it was hard to find good tyres for the NC30’s 18” rear wheel. I started looking for a 5.0 x 17” rear. Luckily, Honda decided that the pre-’94 VFR750 was lacking grip when leant over. For the ’94-’97 model they left the tyre size the same at 17”, but narrowed the rim from 5.5” to 5.0” to increase its round profile. The ’94 bike’s
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The 17” rear-wheel conversion and a stock 18”
There are two halves to an NC30 fuel tap: the on/off reserve half uses a ballbearing that seats in a rubber grommet. By the time the bike is ten years old, the rubber seats will have worn so much that fuel can leak through, turning the vacuum-controlled diaphragm on the tap into your last line of defence before fuel mixes with engine oil in the sump. The infamous HRC tap conversion leaves the diaphragm wide open, which on older bikes would leave fuel free to leak into the oil sump and potentially cause major failure. For a quick diagnosis, pull out the dipstick and sniff it: if petrol’s mixing with engine oil, you’ll be able to smell it. I’m not ashamed to use other people’s components. I use Tyga’s fairings and exhausts – www.tyga-performance.com.
Top quality radiator replacements on the NC30
Buying Honda V4s can cost you a lot of money. NC30s are my choice for a practical V4: they have historical validity, fantastic handling, and are good value besides. If I was looking for a 750, my heart would rule my head and I’d choose an RC30. If you don’t have a mechanical inclination, find the lowest mileage and closest-to-standard NC30 your budget allows. There is a perceived added value to the UK model, but I don’t think there’s much to be gained over the Japanese equivalent. If you’ve found one to buy, check over the charging system and look at where the front cylinder front pipes go into the collectors on bikes with standard exhausts fitted. This area is made from mild steel and always rusts through.
Aftermarket reg/rec: bigger than the original
Rick’s Cr e dit List
Rick would like to thank Nick Townshend for his hub conversions; Mike at HQ Fibre Products for his seat units; Robby Ramage for yokes and suspension linkages; Dean at DJ Fabrications for subframes; Keith at CM Engineering for carburettor parts; Dave and Richard at R&D Precision for their fork tops and alternator conversions; Keith and Darren at Radtech for their radiators; and Ellis at MPE for his gearbox parts. Also the kind people at Jaycee, Ignitech, PDQ, HEL, Venhill, Talon and Electrex.
£6 resistor does job of £100 HRC derestrictor
contact: Rick Oliver: email ricknc30@gmail.com