Suzuki RM-Z450 Specs, Horsepower & Performance Review
TL;DR
- The 2027 Suzuki RM-Z450 is a 449cc, fuel-injected, kick-start-only motocross bike with a $9,699 MSRP.
- Suzuki claims a 247 lb curb weight, 37.8 in. seat height and 1.7 gal. fuel tank.
- A dyno run on the 2025 model showed roughly 55 hp near 8,800 rpm, with the best power in the low-to-mid range.
- New for 2027: KYB fork and shock, RK Excel rims, a reshaped air cleaner outlet and a quieter muffler.
- It is a closed-course race bike, so no independently tested top speed exists. Gearing decides that number.
The Suzuki RM-Z450 is Suzuki’s 450cc motocross race bike. For 2027 it gets new suspension, wheels and a quieter exhaust, and it costs $9,699 (Suzuki Motor USA, 2026). Here is what the specs say, what the dyno shows and where the bike still has gaps.
Suzuki RM-Z450 Specs at a Glance
The 2027 RM-Z450 pairs a 449cc DOHC single with a five-speed gearbox, an aluminum twin-spar frame and a 247 lb claimed curb weight. The table below covers the figures riders ask about most.
| Spec | 2027 Suzuki RM-Z450 |
|---|---|
| Engine | 449cc, four-stroke, liquid-cooled, single-cylinder, DOHC |
| Bore x stroke | 96.0 x 62.1 mm |
| Compression ratio | 12.5:1 |
| Fuel system | Fuel injection, 44 mm throttle body |
| Transmission | 5-speed constant mesh, wet multi-plate clutch |
| Starter | Kick only, automatic decompressor |
| Final drive | D.I.D 520 chain, 114 links |
| Front suspension | KYB inverted fork, 12.2 in. travel |
| Rear suspension | KYB link-type shock, 11.8 in. travel |
| Brakes | 270 mm front disc, 240 mm rear disc |
| Tires | 80/100-21 front, 110/90-19 rear, Bridgestone Battlecross X30 |
| Wheelbase | 58.3 in. |
| Ground clearance | 13.0 in. |
| Seat height | 37.8 in. |
| Curb weight (claimed) | 247 lb |
| Fuel capacity | 1.7 gal. |
| MSRP | $9,699 |
Source: Suzuki Motor USA 2027 RM-Z450 specifications. Suspension travel and rotor sizes from Ultimate Motorcycling’s 2027 first look.
How Much Horsepower Does the Suzuki RM-Z450 Make?
The RM-Z450 makes roughly 55 hp at the rear wheel, peaking near 8,800 rpm. Motocross Action measured 54.87 hp at 8,800 rpm on a 2025 model (Motocross Action, 2025). Another line in that same test lists 56.6 hp at 9,000 rpm, so treat 55 to 57 hp as the working range.
The shape of the curve matters more than the peak. Power builds early, feels strong in the midrange and drops off quickly above 9,000 rpm. Short-shifting keeps the engine where it pulls best.
Every new RM-Z450 comes with either Suzuki’s MX-Tuner 2.0 smartphone app or a plug-in fuel coupler for changing fuel and ignition maps. One catch: the bike has no battery, so the app needs an external one.
That dyno run was on a 2025 bike. Suzuki’s 2027 change list does not mention engine internals, but the reshaped air cleaner outlet could shift throttle response. No independent 2027 dyno has been published yet.
What Changed on the 2027 Suzuki RM-Z450?
The biggest 2027 change is suspension: KYB replaces the Showa fork and BFRC shock. Suzuki also added new wheels, a reshaped intake outlet, a slimmer subframe and a quieter muffler, and the price rose $300 over 2026 (Ultimate Motorcycling, 2026).
- A new KYB fork with a revised upper bracket and larger-diameter inner tubes.
- A new KYB shock meant to improve bump absorption and traction.
- RK Excel rims, with the Bridgestone Battlecross X30 tires carried over.
- A reshaped air cleaner outlet to feed the throttle body more efficiently.
- A muffler with revised internals that meets AMA and FIM sound limits, plus a straighter handlebar bend.
The fork has full damping adjustment but no spring preload adjustment. Suzuki’s site currently lists a free Pro Circuit T-6 exhaust and Ken Roczen replica graphics kit with a new purchase. Confirm the offer with your dealer before you buy.
How Does the RM-Z450 Handle on the Track?
The RM-Z450 is known for quick, effortless turn-in. Narrow bodywork and a comfortable bar bend make it easy to move around on the bike.
The weak points were on the old setup. Testers found the previous Showa shock struggled over repeated bumps and the 270 mm front brake was strong but grabby. The 2027 KYB units target the suspension complaint directly, though no independent track test has confirmed the fix.
Weight is the other thing to know. Suzuki claims 247 lb. The 2025 test measured 241 lb without fuel, which is not light by 450 standards. Sharp handling hides some of that on tight tracks.
Does the Suzuki RM-Z450 Have a Top Speed?
No published or independently timed top speed exists for the RM-Z450. It is a closed-course competition bike, built for short straights and tight turns, so a street-style top speed figure does not apply. Real-world speed depends on sprocket choice, track surface, rider weight and how far you can run before the next corner.
Some spec sites list numbers between about 130 and 145 km/h with no named test behind them. This article does not repeat them.
For a number you can use, look at gearing and power instead. The 449cc engine, five-speed gearbox and 520 chain are all swappable with different sprockets, so you can tune final drive to your track.
Is the 2027 Suzuki RM-Z450 Worth $9,699?
It is worth it for riders who want an easy-to-ride 450 with sharp cornering and a usable midrange. It is a weaker fit if you want the most top-end power, electric start or a bike with proven 2027 test results.
What works in its favor:
- Predictable low-to-mid power and quick turn-in.
- Traction control and the S-HAC holeshot assist system, plus easy tuning.
- Fresh KYB suspension on a proven chassis.
What counts against it:
- Kick start only, with no electric start option.
- Power fades above 9,000 rpm.
- A 247 lb claimed weight that sits on the heavy side.
- No independent 2027 test results yet, so the new suspension is unproven outside Suzuki’s claims.
Best for: intermediate to advanced racers and track-day riders who like a planted, easy-to-read bike. Beginners moving up to a 450 may prefer a bike with electric start.
Suzuki RM-Z450 FAQ
Is the Suzuki RM-Z450 street legal?
No. Suzuki sells the RM-Z450 as a competition motocross bike for closed courses. It is not built or registered for public roads, so it belongs on a track or private land.
How much does the 2027 Suzuki RM-Z450 weigh?
Suzuki claims a 247 lb curb weight. The 2025 model weighed 241 lb without fuel on a test scale. Add fuel and the ready-to-ride number goes up.
Does the RM-Z450 have electric start?
No. It has a primary kickstarter with an automatic decompressor. Suzuki has kept kick start on both RM-Z models for 2027, so the bike has no starter battery.
What spark plug and chain does the RM-Z450 use?
The spark plug is an NGK DIMR8C10. The chain is a D.I.D 520DMA2K with 114 links. Check the owner’s manual before ordering parts if you have changed sprockets.
How much fuel does the RM-Z450 hold, and how tall is the seat?
The tank holds 6.3 L (1.7 gal.) and the seat height is 37.8 in. Ground clearance is 13.0 in.
