2007 Suzuki RMZ 450 Specs and Review

The Suzuki RMZ 450 is highly regarded by both the racing and motorcycling communities, being the first 4-stroke wheeler ever to grace the podium of the AMA Supercross Championship. It effectively captures Suzuki’s brand strengths with its airy and light feel, handling mannerisms, and unrivaled steering precision.

In this article, you’ll learn more about the 2007 RMZ 450 and how this MX-style dirt bike contributed to the prestige of the Suzuki product lineup.

The 2007 Suzuki RMZ 450 is a 449-cc MX-style dirt bike that comes from a long line of award-winning motorcycles. It featured excellent suspension, titanium components, and a racy, sleek design and was the last in its series to receive a 4-speed transmission (along with the Ricky Carmichael Replica).

The 2007 Suzuki RMZ450 performed as superbly on the tracks as it looked good on paper (its MX/SX championships are more than enough proof).

But at the same time, it fell short on producing optimal top end and torque. Was this due to its inadequate 4-speed transmission? And was Suzuki right in going the route of a 5-speed gearbox? Read on if you want to find out the answers to these questions and more.

The Last of the Mohicans

This 1992 narrative comes to mind when thinking of how to describe the 2007 Suzuki RMZ 450. The plot is in no way similar to how this production bike was built. But they do have one thing in common – they are the last of a breed. In the case of the RMZ 450, it’s the last in its series to have a 4-speed gearbox.

Dropping the 5th gear was more than reasonable since Suzuki aimed to make the 450-cc RMZ as lightweight and nimble as possible – just like a 250-cc motorcycle. However, many riders back in the day disapproved of this decision as it rendered the dirt bike lacking in the versatility of a 5-speed transmission. Furthermore, they felt that the 4-speed gearbox made for an odd stock gearing and limited the wheeler’s power spread.

Despite the dirt bike’s smooth-shifting, sound motor package and near-perfect clutch, the Japanese firm eventually gave in to consumer clamor and switched to a conventional 5-speed gearbox the following year. Unsurprisingly, this change did not drastically improve the bike’s performance (you’d probably still need a gear swap and an aftermarket pipe to really open up its top-end). It signaled the end of the 4-speed era for the award-winning motorcycle.

2007 Suzuki RM-Z450Z Ricky Carmichael Replica

To commemorate its first-ever 4-stroke win in the AMA Supercross Championship, Suzuki released the 2007 Suzuki RM-Z450Z Ricky Carmichael Replica. This limited-edition trim received special Team Makita Suzuki graphics, sand-cast cases, yellow-colored wheels, a Pro Circuit exhaust, and a black saddle just like Ricky Carmichael’s RM-Z450.

But that’s not the best part. If production bikes were easy to ride, this special trim did the same but fast (thanks to its added horsepower). Only 1,000 units of these were produced in the U.S.

2007 Suzuki RMZ 450 Specs & Features

Engine

The 2007 RMZ 450’s power mill is a liquid-cooled, single-cylinder 4-stroke DOHC. It has a bore-stroke ratio of 95.5 mm x 62.8 mm (3.760 x 2.472 inches), 11.9:1 compression ratio, and piston displacement of 449 cm3 (27.4 in3).

What’s special about this engine is that it’s the first Japanese MX-style bike of its class to win the AMA Supercross Championship. A Keihin FCR40MX carb and a polyurethane foam filter element handle the air-fuel mixture. Overall, the engine’s layout yields the following performance figures:

Description	Unofficial, from online sources
Top Speed	70 mph (113 km/h), on stock gearing
Horsepower	50.2–58.5 hp (36.9–43 kW) @ 8,800 RPM
Maximum Torque	45 Nm (4.6 kgf-m, 33.2 lb-ft) @ 7,600 RPM

If you ever have the misfortune of blowing your bike’s stock exhaust, you wouldn’t be able to just swap it out for an earlier model pipe. Because of upgrades received that year, the ’07 model had odd-sized components.

The most preferred replacement choices are the 4.0 Titanium FMF Muffler Slip-on, the Pro-Circuit Ti-5 System (view on Amazon), and the Yoshimura RS-2 Exhaust System (view on Amazon).

Except for the FMF slip-on, these aftermarket pipes are designed as a full-race exhaust system inclusive of a sturdy mounting bracket, USFS-approved spark arrestor, and CNC-machined exhaust flange. They may require minor tweaks to perfectly fit the RMZ450.

Trivia: Some online sources and motorcycling publications confuse the ’07 and ’08 RMZ450 models, stating that the 2007 version is equipped with FI and a 43-mm throttle body idling @ 2,000 ± 100 RPM. Those changes did not take place until the following year. As proof, even the limited-edition Carmichael Replica has a Keihin T FCR40 carburetor and only a 4-speed gearbox.

Fuel & Lubrication

The lubrication system is a semi-dry-sump type. Lube capacities for standard models are as follows:

• 1.2 L (1.3 US quarts, at draining)
• 1.25 L (1.3 US quarts, at oil filter change)
• 1.3 L (1.4 US quarts, at disassembly)

Use of SAE 10W-40 Performance 4 Motor Oil or its equivalent with a minimum SJ API grade meeting JASO T903 MA standards is strongly advised. Following ambient temperatures, other viscosity grades stated in the service manual are allowed for use.

Fuel-wise, capacity is 7.0 L/1.8 USgal of unleaded gasoline with a rating of at least PON 90/RON 95. Gasohol variants with no more than 5% MBTE, 10% ethanol, or 5% methanol are permitted. As the fuel tank capacity is limited, owners can opt for 12-L/3.2-USgal capacity IMS Fuel Tanks specifically made for 2005–2007 RMZ450s. They are slim and made of cross-linked Polyethylene material, both strong and durable.

Drivetrain

A 4-speed, constant-mesh transmission with a wet multi-plate centrifugal-type clutch assembly delivers power to the ground for the 2007 RM Z450 model. The shift sequence is 1-down 3-up and is one gear short than its smaller-displacement cousin, the 1975 Suzuki RM 125. A DID 520 MXV chain (with 114 links) handles wheelspin. Stock gear ratios are listed below:

Description	2007 RMZ 450	2008 RMZ 450
Primary Reduction Ratio	2.583 (62/24)	2.625 (63/24)
Transmission Gear Ratio (1st)	2.000 (30/15)	1.800 (27/15)
Transmission Gear Ratio (2nd)	1.611 (29/18)	1.471 (25/17)
Transmission Gear Ratio (3rd)	1.363 (30/22)	1.235 (21/17)
Transmission Gear Ratio (4th)	1.166 (28/24)	1.050 (21/20)
Transmission Gear Ratio (5th)	N/A	0.909 (20/22) @ Top gear
Final Reduction Ratio	3.500 (49/14)	3.846 (50/13)
Gearshift Pattern	1-N-2-3-4	1-N-2-3-4-5

Ignition

An electronic CDI (Capacitor Discharge Ignition) and primary kick-start system easily bring the dirt bike to life (thanks to automatic decompression). An NGK DIMR8A10 spark plug with a gap of 0.9–1.0 mm (0.035–0.039 inch), a tightening torque of 11 Nm (1.1 kgf-m, 8.0 lb-ft), and a timing of 15° BTDC @ 1,950 ± 100 RPM is responsible for spark ignition.

Meanwhile, a magneto with a rated output of 95 V (AC, no-load voltage) @ 5,000 RPM serves as its charging system and power source for lighting and electronic accessories (if any).

Since the RM-Z450 doesn’t have an electric start, it also means it doesn’t have an on-board battery. It is best to visit your nearest Suzuki dealer or consult a professional mechanic should you wish to equip it with one. Ask if a YB12B-B2 or YB10L-A2 battery (view on Amazon) will work with the two-wheeler since most Suzuki 400/450-cc motorcycles use the same format.

Tires & Brakes

Stock rubber consists of 90/100-21 M401A/M201 and 120/80-19 M402A/M202 front/rear tires, or 90/100 R21 51M and 120/90 R19 57M front/rear Bridgestone® tires. These knobbies are mounted on aluminum wheels (1.60×21 front; 2.15×19 rear) for reduced slippage and improved grip on slick surfaces and MX tracks.

Recommended cold-tire pressure for both is 70–110 kPa (0.7–1.1 kgf/cm2, 10–16 psi). For its stopping power, the RMZ450 relies on dual hydraulic discs.

Suspension

Enclosed in the dirt bike’s twin-spar frame (25° 30′ caster angle; 108 mm/4.25 inches trail) are front (cartridge-type) telescopic forks and a link-type rear swingarm. These units provide generous wheel travel at 310 mm (12.2 inches) each.

They are also mated to a turning radius of 1.95 m (6.4 feet) and 1,480-mm (58.3-inch wheelbase, making for superb handling and cornering angles – especially on technical trails. Minimum ground clearance is also not too shabby at 350 mm (13.8 inches).

Dimensions & Capacities

The RM-Z450’s overall dimensions are 2,185 x 830 x 1,260 mm (86 x 32.7 x 49.6 inches). Seat height is 37.6 inches, while dry weight is 100 Kg (220 lbs.) – almost 20 Kg more than Suzuki’s 125-cc motorcycles.

Exterior

Although the 2007 Suzuki RM-Z450 mostly received mechanical upgrades, it also sported cosmetic changes that gave it an even more aggressive look. For instance, the dirt bike’s radiator shrouds (while redesigned to improve its cooling function) added to the RMZ’s sportiness. Its titanium head pipe and aluminum muffler had a similar effect.

The bike came standard with handgrips, handlebars, front fender, exterior covers, and fork guards and was available in Champion Yellow. The footpegs and headpipe were made of titanium, and a Renthal Fatbar was standard.

If you want to make your two-wheeler street-legal, you’ll need to add lighting, turn signals, a license plate holder, and a horn (among others). A Trail Tech Black Vapor Digital Speedometer (view on Amazon) and a 12V battery will be great additions to your motorcycle.

How Much Is a 2007 RMZ 450?

The 2007 Suzuki RZM450 MSRP is $6,799 – $300 more than its first production model. It would be worth at least $9,300 if sold brand-new today. Note that this value is only true for base models and excludes dealer inclusions or aftermarket mods.

The 2007 RMZ450 Ricky Carmichael Replica is a special trim produced by the Japanese firm to celebrate the previous year’s AMA Supercross success. It is only $200 more than the dirt bike’s standard version.

The table below shows how the ’07 RM-Z450 price compares to the rest of the model years in the series:

Year – Model – Trim	List Price	Retail/Trade-In Values
2005 Suzuki RM-Z450K5	$6,499	$675 – $885
2006 Suzuki RM-Z450K6	$6,599	$710 – $3,799
2007 Suzuki RMZ 450K7	$6,799	$750 – $990
2007 Suzuki RM-Z450Z Carmichael Replica	$6,999	N/A
2008 Suzuki RM-Z450K8	$7,199	$1,000 – $1,315
2009 Suzuki RM-Z450K9	$7,899	$1,250 – $1,645
2010 Suzuki RM-Z450LO	$8,099	$1,615 – $2,125
2011 Suzuki RM-Z450L1	$8,149	$1,795 – $2,360
2012 Suzuki RM-Z450L2	$8,399	$2,050 – $2,700
2013 Suzuki RM-Z450L3	$8,699	$2,145 – $2,825
2014 Suzuki RM-Z450L4	$8,699	$2,735 – $4,579
2014 Suzuki RM-Z450 LE Matt Moss Team Motul Pirelli Race Replica	$11,339 / $13,990 AUD	N/A
2015 Suzuki RM-Z450L5	$8,749	$3,105 – $4,085
2016 Suzuki RM-Z450L6	$8,749	$3,575 – $4,705
2017 Suzuki RM-Z450L7	$8,749	$4,045 – $5,325
2018 Suzuki RM-Z450L8	$8,949	$5,225 – $8,899
2019 Suzuki RM-Z450L9	$8,949	$5,815 – $8,000
2020 Suzuki RM-Z450M0	$8,999	$6,755 – $8,890
2021 Suzuki RM-Z450M1	$8,999	$7,180 – $9,450
2022 Suzuki RM-Z450M2	$8,999	N/A

As for auction listings, most of the pre-owned dirt bikes posted for sale are iterations from 2014 to 2020 and were used by motorsports companies. There are very rare postings of 2007 RMZ 450 models in the used-bike market. If owners aren’t willing to let go, it can only mean good things about the dirt bike’s build quality.

Updates for 2007

In the words of motorcycling publications who witnessed the launch of the 2007 Suzuki RM-Z450, there were about “200 changes” done to the firm’s flagship dirt bike. I wouldn’t be able to list everything in this article. But I went ahead and compiled the most significant:

• The combustion chamber, intake port, and carburetor settings were revised to optimize intake efficiency and enhance low-to-midrange power.
• Its exhaust pipe is extended by 85 mm, effectively improving power output.
• Piston oil-control rings received chrome-nitride coating, improving oil sealing and reducing friction.
• Oil strainer was made accessible, eliminating the need for removing the crankcase in the process.
• The scavenging pump was also redesigned to be more durable and for better lubrication.
• Fuel combustion and overall efficiency were improved – thanks to variable ignition timing provided by an optimized 3D-mapped ignition.
• The twin-spar aluminum-alloy frame was updated.
• Thicker lower tubes and thinner tank rails enabled the 2007 RMZ 450 to achieve better cornering performance and straight-line stability. Revised swingarm and front/rear shock settings had the same aftereffect.
• In addition to aggressive new graphics, the bike also received a new saddle with textured side panels for increased knee grip.
• Suzuki made a slew of other changes to the brake rotors, side covers, fork protector, etc., to shed weight off the MX bike.

2007 RMZ 450 Problems

Despite being essentially a ‘commemorative’ production model, the RMZ450 was not without its flaws. Severity-wise, most of the bike’s imperfections were minor. But in terms of how functionality is affected, there were some pretty pesky ones. One example is the placement of the motorbike’s carb-mounted hot-start lever. Not only is accessing it a huge hassle but the bike’s unexpected ‘flame out’ episodes also worsen the issue.

The airbox has a somewhat similar problem – in the sense that it’s also difficult to use, making air filter removal tedious. Other noteworthy issues with the ’07 model are its tall 1st and 2nd (stock) gears, less flexible 4-speed gearbox, and being a victim of the cough-and-die syndrome (although this last one is not exclusive to the Suzuki RMZ 450 motorcycle).

About Suzuki

Suzuki Motor Corporation is an automotive powerhouse headquartered in Hamamatsu, Japan, and one of the “Big 4.” Before it produced the likes of the 2007 Suzuki RMZ 450, this firm was the first part of Japan’s silk industry and a manufacturer of weaving looms.

It wasn’t until three decades later that founder Michio Suzuki decided to diversify and venture into the world of automotives. What began as a small production of prototype cars in 1937 has evolved into a Japanese conglomerate with 133 distributors in 92 countries and over 68,499 global employees.

Conclusion – 2007 Suzuki RMZ 450 Review

This MX bike can be challenging to keep on the pipe at times. To add, it isn’t perfect, and like most other motorcycles, it would benefit from gearing adjustments, extra ponies, and a few mods here and there.

But if there’s anything the 2007 Suzuki RMZ 450 is not is being inadequate. Missing gear or not, no dirt bike deemed lacking in competencies would be able to manage smoking its competition in the AMA Supercross. Nor would it have a Carmichael Replica limited edition.