Honda NS400R (1985-1988) - Review & Buying Guide

Race replicas were big business in the 1980s. Giving race fans the opportunity to buy lookalikes of the factory machines they watched on track was a marketing masterstroke – who didn’t want to be Freddie Spencer, Barry Sheene, or Kenny Roberts?

Yamaha was first to debut a road going version of its 500 GP racer. The RD500LC (RZV500R in Japan) created a sensation as the world’s first V4 two-stroke road bike. Suzuki followed with the RG500 Gamma, an even closer approximation of its racer, that was faster, lighter, and more powerful than the RD.

Honda’s response was slightly different. With one eye on the hugely lucrative home market, the big H opted instead to create a 400 – more of a nod to its championship winning NS500 race bike than a replica.

Compared to the RD and RG the NS was more a 250 on steroids than a blue riband class replica. Indeed the 400R’s chassis was borrowed from the NS250R, and even its engine was a revamp and upscale of the old MVX250 unit. But what the NS lacked against its rivals in outright power, speed and numbers on the side of its fairing it more than made up for in nimble handling, luxurious build quality, beautiful styling and – for Spencer fans – Fast Freddie appeal.

Now, almost 40 years on, the NS’s then shortcomings have become its biggest asset. The NS is judged slightly differently to the RD and RG precisely because it’s not a 500 and that reflects in price. While Suzuki and Yamaha values continue to sky rocket from the ridiculous to the absurd (£20K-plus is now normal for either) the Honda remains far more affordable while still offering a similar GP fantasy. Like 10 grand plus more affordable. And that’s why Honda’s little V3 has become the pick of the big GP reps. Buy now, while you still can…

Honda NS400R (1985-1988) - Price

Honda first released the NS400R in 1985. Although it remained in the range until the end of 1987, only two models were produced – the first year R-F and 1986 R-G – which were identical in everything other than model year designation. Japanese import models are common and easy to spot, featuring a wrap around style front mudguard, faired in front indicators, km/h speedos, and speed warning light on the dash. Japanese bikes are restricted to 59bhp. South African bikes (only 50 were produced for homologation purposes) run NS250R pistons in 1mm smaller bores, giving a lesser capacity of 373cc.

Honda NS400R-F (1985) and NS400R-G (1986) values:
Rough £4000-£5000;
Tidy £6000-£9000;
Mint £10,000-£12,000

The first models to reach the UK (March 1985) were in HRC colours; Rothmans replicas didn’t land until August than year. Frame and engine code number NC19. Chassis and bodywork shared with the V-twin Japan only NS250R. 70bhp, 163kg. R-G model, no changes. Colours: red/white/blue/yellow (HRC), Rothmans replica blue/white

Honda NS400R (1985-1988) - Engine & Performance

The NS400R isn’t a replica. Its engine shows as much. For starters it’s a different displacement to Honda’s 500cc racer – by a deficit of 112cc. Its layout is the opposite of the NS500 too, with two front cylinders and one rear pot as opposed to the racer’s two top and one bottom.

The road bike’s lesser capacity and inability to compete wheel to wheel with Yamaha’s RD500LC and Suzuki’s RG500 was a direct result of Japan’s licensing laws. The 400cc class was massive in Japan during the 1980s due to draconian legislation making it both hard and expensive for riders to obtain a big bike licence, so making the NS a 500 wouldn’t have helped home-market sales.

Its reversed engine architecture compared to the NS500 racer was down to two things. Firstly Honda already had a two-stroke V3 engine in its MVX250, and the 400 was a development of that, and secondly the NS’s chassis – the same as used for the V-twin NS250R – was a perfect fit for a two-down, one-up triple-vee.

Both bore and stroke were increased from the MVX’s 47mm x 48mm to 57mm x 50.6mm (making 387cc rather than a full 400), cases and internals strengthened (much needed after unreliability plagued the MVX’s reputation), and Nikasil coating was added to the cylinders to minimise friction, heat, and wear. Indeed, the NS400R was one of the first production machines to use the tech.

Honda’s GP-developed ATAC system was employed on the front two cylinders. Unlike Yamaha’s YPVS system which alters export timing via a moving valve, ATAC (Auto Controlled Torque Amplification Chambers) alters two-stroke exhaust volume by utilising chambers located just after the exhaust ports. At low rpm the chamber are open, increasing torque. At higher rpm the chambers close to optimise top end performance.

Honda claimed 72bhp at 9500rpm for its V3 (59bhp in home market spec), which was less than both RD and RG500, but compared well against Yamaha’s RD350 YPVS and made the NS feel more like a fast, torquey 250 than a full-on GP replica. A top speed of between 126-135mph, depends on conditions and rider weight, and proved a good match for Yamaha’s Power Valve 350 too. Fuel consumption can be heavy, however, dropping as low as mid-20s if ridden hard.

Honda NS400R (1985-1988) - Handling & Suspension (inc. Weight)

As previously mentioned, the NS400R wasn’t developed from scratch like the RD500LC or RG500 Gamma. Instead, Honda shoehorned the V3 engine into the same frame as its V-twin NS250R – the 1984 replacement for the MVX250 that, ironically, gave its engine architecture to the 400…

The NS’s box-section aluminium perimeter frame proved perfect for the 400, however, giving the bike sharper handling that either RD or RG500. Indeed at the time many testers thought the NS to be the finest handling street bike on the market. At 160kg dry, the 400R was only 16 kilos heavier than the NS250R (yet 14bhp more powerful in Japanese spec; 27bhp more in export spec), so flicking it from side to side was and still is a breeze.

For a bike now almost 40 years old the NS400R still dazzles with its level of sophistication and build quality. The swingarm – aluminium alloy like the frame – is subtly braced and detailed like something out of HRC’s race shop. The 37mm telescopic forks are air-assisted, TRAC anti-dive equipped, and wrapped in trick aerodynamic shrouds. The shock was state of the art for 1985; a rising-rate system with preload adjustment via a remote knob under the left side panel.

Lightweight pressed aluminium Comstar wheels, just like those on the NS500 and NSR500 racers, sit on tubeless V-rated tyres, 16in front and 17in rear. Only the tyre sizes betray the true age of the NS, being super skinny 100/90 and 110/90 in profile. Twin-piston calipers gripping 256mm discs upfront, with a single-pot caliper and 220mm as rear back up, proved more than adequate in stopping this racy two-stroke.

Handling is still an NS strength, although tyre choice is getting harder – a swap to wider CBR600 wheels is a popular mod. The riding position is less extreme than later race replica, especially 250s, so the NS is comfortable over distance too, and shown a twisty back road it’ll still impress with its agility and willingness to turn.

Honda NS400R (1985-1988) - What to look for

Bodywork: Getting scarce. Know too that Japanese bikes run a different fork leg hugging front mudguard, as well as faired-in front indicators. The Japan-only NS250R V-twin shares some interchangeable parts, but always cross reference part numbers first.

Gearbox: Early bikes can jump out of gear. Honda improved the gearbox on later models (86-onwards), but the mods were never retrofitted, so newer bikes are a better bet in this regard. Get a test ride before buying, if possible; if it jumps out of lower gears under load there’s likely an issue with the engagement dogs.

Engine: Reliability is generally good, but be realistic. These are 35-year old two-strokes, so issues are possible. Low mileage isn’t necessarily a good thing. Lack of use can cause internal seals to harden. Failed crankcase seals will allow gearbox oil to be drawn through into the cylinders – thick white smoke is the most obvious sign. If an engine’s been rebuild, ask to see receipts and/or old parts. Only the two front cylinders feature ATAC – the electronically control volume changing tech; check that the chambers open and close as they should.

Frame: A work of art, but now old enough to warrant close inspection to check all welds are still solid. Right-side down tubes are bolt-on to aid engine removal. Chewed or marked Allen heads will indicate if the motor’s even been out.

Exhausts: The NS’s standard pipes look trick, but they’re heavy, restrictive and quiet. Indeed, rather than sounding like a snarling GP rep, a stock NS makes a noise more akin to a trio of muffled mopeds. After market pipes save weight, release extra ponies and add a crisp bark to the engine’s antics. Carbs will usually require rejetting to suit, however.

Wheels: The bolt together Comstars are light in weight and mimic the design of the NSR500 racer of the time, but Honda do not recommend that they are taken apart. 100/90 16, 110/90 17 tyre sizes are quite restrictive too; replacing hem with early CBR600 wheels for slightly wider tyre choice and a 17in front is a recognised mod.

Tuning: There’s potential in the NS’s motor, especially with a 475cc big-bore kit, but such an upgrade is expensive – more than £2000, and you’ll need pipes, jetting and ancillaries to suit.

Honda NS400R (1985-1988) - Rivals

Honda VF500F is a brilliant middleweight V4 that unfortunately and unfairly suffered due to the reliability fall out from the VF750S/F. Sweet handling chassis, well built and thoughtfully detailed, but thirsty on fuel and lack the later V4’s gear-driven cams. Exhausts rot for fun. Find one in fine fettle, however, and you’ll have a blast for a lot less dosh than an NS400R.

The best 1980s GP replica was the Suzuki RG500. Closer to its racing inspiration in both tech and performance than the NS or RD – tuned RG500 engine can make north of 125bhp (that’s more, per litre, than an S1000RR). Stock bikes don’t quite match the hype, however, and prices are now ludicrous purely because the RG is the best of the big 2Ts.

A tribute to Kenny Roberts and Eddie Lawson, the Yamaha RD500LC was a revelation back in 1984. But in reality the 500LC is just a big pussy cat. Very flexible and torquey in delivery, it’s actually a really decent road bike – if you can afford the fuel bill. Not as sharp as the RG, or as jewel-like as the NS. Damn expensive, though. RZV500R has an aluminium chassis, but a touch less power.

Honda VF500F, 1985 | Approx Price: £1800-£3000

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Power/Torque

70bhp / 31.8lb-ft

Weight

185kg

Suzuki RG500, 1985 | Approx Price: £12,000-£20,000

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Power/Torque

95bhp / 53lb-ft

Weight

156kg

Yamaha RD500LC, 1984 | Approx Price: £12,000-£20,000

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Power/Torque

88bhp / 48.4lb-ft

Weight

180kg

Honda NS400R (1985-1988) - Verdict

There are only three Japanese 500 class race replicas. Honda’s NS400R is by far the best value; RD and RG prices are now ridiculous whereas the NS is still affordable and its build quality and engineering goes a long way to justifying its value. Indeed the NS is such a beautifully built, well put together, ahead of its time design that it’s right up there with Honda’s other great race reps like the RC30, CBR400RR NC29, and NSR250R MC28. Buy one now. They’ll only be this affordable for a short while.

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Honda NS400R (1985-1988)- Technical Specification

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