Known for its aggressive design, impressive handling, and rider-friendly mannerisms, the Yamaha RT100 was many off-roader’s first motorbike. It may not have insane performance figures and styling. However, a challenging yet slightly forgiving nature was all it required to get nouveau and recreational riders hooked — as you will soon find out in this comprehensive guide.
The Yamaha RT100 is an Enduro-styled two-wheeler produced from 1990 to 2000. It has a 97cc power mill, stark, rugged styling, and robust suspension (paired with an almost-8-inch ground clearance), and it is a great bike for beginners and off-road enthusiasts.
The RT 100 — A Short-Lived Off-Road Classic
The Yamaha RT100 has a rich history that traces back to its introduction in the late ’80s. Since its inception, it was designed to cater to gearheads seeking a capable but unintimidating dirt machine that could easily handle various terrains. But despite its seemingly precedented reputation, there seems to be little to no online material about the history and conceptualization of this 100cc wheeler.
The lack of published literature about the bike does not make it any less of a thriller. Because of its competencies and manageable size, it has become extremely popular with young riders and learners.
Don’t get me wrong — you will not find a reverse included in its gearbox or a rev limiter. Nonetheless, the two-wheeler feels safer as a learning platform than jumping straight to a 350-cc or 450-cc speedster.
1999 Yamaha RT 100 Specs & Features
Engine
The dirt bike has an air-cooled, forward-inclined, single-cylinder 2-stroke engine. This power mill has a 52 × 45.6 mm (2.047 × 1.795 inches) bore-stroke ratio, a 6.7:1 compression ratio, and a piston-controlled intake and exhaust valve design. Engine displacement is 97 cm3 (5.9 in3), delivered by a Mikuni VM22SS carb.
Overall, this engine configuration lends to the following performance figures:
| Description | |
|---|---|
| Yamaha RT 100 Top Speed | 45–50 mph (72–80 km/h) |
| Horsepower | 6–8 hp (4.4–5.9 kW), estimated |
| Maximum Torque | unspecified |
| Fuel Economy | 60–70 mpg (3.4–3.9 L/100 km, 25–30 kmpl) |
| Approximate Tank Range | approximately 72–92 miles for a full fuel tank |
TIP: The power mill can be swapped for a Mikuni TM24 or a Keihin PWK28 to increase airflow and improve fuel delivery. Depending on how much you increase overall power and performance, this upgrade may entail adding a larger fuel tank and high-performance exhausts (view on Amazon) on the motorcycle.
Fuel & Lubrication
It has a Yamaha Autolube lubrication system — a proprietary oil injection system that utilizes a mechanical oil pump and is ECU-controlled. Required engine oil is 1 L of SAE 10W-30 Yamalube 2-cycle oil or its equivalent, with a minimum SJ API grade, meeting JASO T903 MA standards (originally JASO FC or ISO EG-C, EG-D grades).
As for the fuel tank, capacity is a bit miserly at 5 L/1.32 USgal. Aussie units warrant unleaded fuel, while all other markets can make do with regular petrol or gasoline. The minimum Octane rating is unspecified in the owner’s manual but can be assumed to be at least PON 87/RON 91.
Drivetrain
A 5-speed constant mesh return system (left-foot operated) and a wet, multi-disc clutch assembly deliver power to the wheels.
A 420 O-ring chain like DID (420V-134) Professional V Series O-Ring Chain with Connecting Link (view on Amazon) handles wheel spin. A traditional front fork system (more on this later) lends to its superb handling and maneuverability. The two-wheeler’s manual transmission has a gearshift pattern of N-1-2-3-4-5, making for intuitive and quick shifting.
For reference, the stock transmission gear ratios are below:
| Description | |
|---|---|
| Primary Reduction Ratio | 3.895 (helical gear) |
| Transmission Gear Ratio – 1st | 3.182 |
| Transmission Gear Ratio – 2nd | 2.000 |
| Transmission Gear Ratio – 3rd | 1.368 |
| Transmission Gear Ratio – 4th | 1.000 |
| Transmission Gear Ratio – 5th | 0.800 |
| Final Reduction Ratio | 3.429 |
Ignition & Electricals
The RT 100 has a fully-transistorized CDI (Capacitor Discharge Ignition) system and a kickstarter waking up the small thumper. A CDI Magneto is its charging system, although the rated output is unspecified in the owner’s manual.
Pre-1993 Yamaha RT 100 models may have a 6V electrical system requiring A 12V upgrade kit, a new charging regulator, and a compatible battery format.
As for spark ignition, it employs an NGK BR7ES plug with an electrode gap of 0.7–0.8 mm (0.028–0.031 inch) and a torque spec of 25 Nm (2.5 m-Kg).
Tires & Brakes
Factory knobbies consist of tube-type Cheng Shin tires measuring 2.50-18 (4 PR) at the front and 3.00-16 (4 PR) at the back. They are mounted on spoked wheels (view on Amazon) with measurements of 18×1.40 and 16×1.60.
Recommended cold-tire pressure for both knobbies is 125 kPa (1.25 kgf/cm2, 18 psi) and is suitable for off-road riding. As for brakes, right-hand/foot-operated drums complete its tire-and-wheel assembly.
Suspension
Conventional front telescopic forks and a rear swingarm are enclosed in a double-cradle frame design. Each unit has oil-damped coil springs (with the rear having spring preload adjustability) and a respective wheel travel of 4.3 inches (110 mm) and 3.1 inches (80 mm).
Despite its short-travel suspension layout, tight curves and hairpin bends can be easily executed with the bike’s 1,190-mm/46.8-inch wheelbase, 5.9-foot turning radius, and 200-mm/7.9-inch ground clearance.
Dimensions
Overall dimensions are 70.7 x 29.9 x 37.8 inches (1,795 x 760 x 960 mm — L x W x H) for Yamaha RT100Ms sold in North America, with slight variations in length, width, and height across different markets. The seat height is somewhat low at 28.7 inches (730 mm). Meanwhile, the curb weight (unladen) is 79 Kg (174 lbs).
The payload limit is unspecified in the owner’s manual. But if based on average values of 150—200 Kg (330—440 lbs.) for same-class thumpers, then we can estimate its GVWR to be around 229 Kg (505 lbs.) — inclusive of the bike’s curb weight, full tank and fluids, cargo, and accessories.
Exterior
On the outside, the Yamaha RT100 looks like your typical Enduro/dirt bike with its high-clearance front fender, narrow profile, and grooved bias tires. The overall styling is stark and aggressive, while the instrumentation is basic and straightforward.
Most production models sported a two-tone color scheme. The front and rear fenders finished in a different hue accentuating the rest of the two-wheeler. In other iterations of the dirt bike, the two-tone ratio is reversed (with only the saddle having a pop of color).
Yamaha RT100 Price
MSRP for the Yamaha RT 100 was $1,349 during its debut. The 1997 Yamaha RT 100, in particular, was sold for $2,049. This listing price remained unchanged until the two-wheeler’s final production in 1999 and 2000.
As for auction listings, the 100-cc motorcycle is currently selling for almost the same value as its original list price. However, expect used bikes to have “okay” cosmetics at best, with slight rust formation on the frame and engine and some missing parts.
Units below $1,000 may have blemishes, dents, leaks, or stains. If you opt for these budget deals, test before buying or have the thumper evaluated by a mechanic.
About Yamaha
Yamaha Motor Company Limited is a well-known Japanese manufacturer. It has gained worldwide recognition for its pioneering role in the ATV industry and exceptional watercraft, motorsport, and off-road contributions.
Established as a reed organ and piano manufacturer, the firm swiftly transitioned into motorcycle production. It achieved remarkable advancements in its ventures and introduced groundbreaking Enduros like the Yamaha RT 100.
Yamaha is globally recognized as a powerhouse in various automotive sectors. It remains committed to its mission of “Kando,” consistently developing products and services that enhance people’s lives.
Conclusion — Yamaha RT 100 Review
Finding a preloved 1995—2000 Yamaha RT 100 in near-mint condition isn’t easy. Typically, owners with bikes in good working condition and minimal cosmetic damage are unwilling to let them go. So if you stumble upon such an irresistible find, I strongly suggest getting your hands on this classic thumper!
Kris is an avid off-roader and outdoor enthusiast who loves to brave the elements and take on challenging terrain. He also enjoys sharing his passion and knowledge with others so that they, too, can appreciate the ride.
About Kris