1964 Yamaha Trailmaster 80

Taking it to the trails

yamaha trailmaster 80 1

1964 Yamaha Trailmaster 80.

Photo by Chris Hartman

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Yamaha Trailmaster 80 
Years produced:
Claimed power: 6.2hp @ 10,000 rpm
Top speed: 41mph
Engine type: 81cc 2-stroke, air-cooled single
Weight (dry): 63.5kg (140lbs)
Price then/now: $367/$1,000 - $2,500
MPG: 170

When you think of a vintage small-bore Japanese motorcycle for running in-town errands or slinging mud on a weekend camping trip, what comes to mind?

For many it’s a Honda Trail 90. But if you want something different, the Yamaha Trailmaster 80, might be the bike for you, and in many respects it surpasses its more heralded competition. 

Out of the shadows
In the early 1960s, Yamaha was best known in America for its larger YD series of machines. It wasn’t until the introduction of the YG series in 1963 (and the lesser-known YJ series of 1964) that the small-bore crowd was treated to Yamaha’s wonderful mix of style, sportiness and 2-stroke innovation.

The Yamaha YG1 was the more mainstream street-oriented machine, with a full front fender, two-place seat and sporty two-tone paint schemes. Today, the occasional YG1 comes up on eBay and would prove an excellent street machine on its own merits. But it’s the YG-1T, or Yamaha Trailmaster 80, that is getting our attention, as it deserves a little spotlight of its own, out from the shadows of the all-powerful Honda Trail.

First introduced in 1964, the Yamaha Trailmaster 80 combined Yamaha’s then-new rotary-disc-valve 2-stroke engine, with a few well-chosen functional modifications to make it better suited for the occasional off-road journey. Items like the cut-down front fender, the small rubber mud flap, the solo seat with a sizeable luggage rack on the back and a skid plate mounted under the engine all work together to shout “Trail.”

In fact, when sitting next to their similar vintage Honda Trail 55 and 90 counterparts, the Yamaha Trailmaster 80 fits right in, yet looks more refined. While the Hondas were based on the step-through Cub C100 series and flaunted their raw look with exposed components, the Trailmaster was based on a sportier street bike, and therefore carries over a few more stylish cues like the gleaming chrome fuel tank and low-mounted
chrome muffler.

Walk around
As with other mid-1960s tiddlers, the stamped multi-layer sheet metal frame forms the foundation, incorporating the central spine, headstock support and rear fender into one robust, yet lightweight, beam. Combined with sheet metal side covers, the frame carries the bulk of this bike’s bold red paint color. Sitting atop the frame is a tear-drop-shaped fuel tank gleaming in polished chrome. Small ribbed rubber kneepads fit snugly on each side, while an early-style Yamaha badge proudly displays its heritage. The comfortable solo seat complements the clean look, while the body-colored luggage rack hangs off the back fender, ready for a bag of groceries.

Up front, a pair of slender telescopic forks are capped by a compact combination headlight and speedometer housing. The front fender is unique to the Trailmaster and features a much slimmer cut compared to the full-bodied shape of the street-oriented YG1’s fender. 

The Yamaha Trailmaster 80 is also unique in running a pair of 16-inch wheel rims, as opposed to the 17-inch setup found on most small street machines. This provides for a bit more clearance under the fenders to allow for a fatter 2.5-inch-wide tire. In fact, there is more than enough room for a 3-inch knobby tire, should one want a more dedicated trail machine.

The well-placed upper controls are simple yet stylish, and mount to a wide chrome handlebar with ample rise and pullback. The throttle, brake, clutch and choke controls are exactly where you would expect. The speedometer has markings up to 60mph (extremely optimistic given the short gearing), as well as neutral and low-fuel lights, even though the bike did not have wiring for the fuel light!

Almost lost in the chrome and gleaming red paint is the little 81cc mill mounted low-down in the frame. Being a rotary-valve 2-stroke, the engine is wider than it is long, and is an extremely light-weight unit, needing only two mounting bolts to secure it to the frame. The carburetor is out of sight, concealed in the right side case, and pulls air from a cylindrical-shaped air cleaner sitting atop the engine. The cylinder head and barrel are aggressively finned while the main engine and transmission cases have a smooth, sculptured look. This is further emphasized by the tightly radiused header pipe that runs into a slender low-mounted chrome muffler exiting well behind the rider’s right foot. The header pipe should retain its shape even after a hit or two thanks to the extremely sturdy pressed-steel skid plate mounted underneath the entire power unit.

Road and trails
Like most small-displacement 2-strokes, it only takes a gentle kick of the starter lever to bring the Yamaha Trailmaster 80 alive. A couple quick jabs of the throttle clears its throat, and it settles down into a lazy idle that produces very minimal buzz in the grips.

Low gear is engaged with little fuss using the combination toe-heel lever, and after a quick check of traffic, I’m off for a short morning ride. As with most trail-oriented bikes fitted with a large rear sprocket, the gearing is exceptionally short, so much so that you find yourself barely 20 feet down the road before needing second gear.

Acceleration is quick, but it doesn’t pile on at the top end of the rev range like most 2-strokers. Detuned for better midrange, this 81cc engine almost feels like a 4-stroke in its behavior, with smooth, consistent power throughout the rev range, with no hint of peakyness. Its only fault is that it gets a little thrashy at the top end of the rev range, which in some respects acts like an audible rev limiter. Third gear proves very useful for zipping around residential city streets, as it has a usable range from a slow roll up to just more than 30mph.

Once you make your way out on busier, faster roads, the short gearing that gives it plenty of in-town zip suddenly proves to be a handicap. Flat out in fourth gear is barely above 40mph. The bike is powerful enough to run higher speeds, so if you don’t have plans for much off-road activity — where the short gearing proves useful — it would be wise to fit a smaller rear sprocket off the Yamaha YG1, which should let this little tiddler climb past 50mph with minimal fuss.

The front and rear damping rates are on the soft side, but they work in harmony when hitting bumps mid-corner. There is a touch more nose dive than I like during hard braking, but again, this is expected from a dual-purpose machine. The brakes are quite small, like most in this class of machine, but they require only a couple fingers to gain maximum clamping pressure.

Like its name suggests, the Trailmaster 80 proved wonderfully capable on loose surfaces. It is rock-solid stable on the straights, yet highly flickable carving through tight third gear corners. Some well-timed use of the rear brake will also prove handy when trying to imitate your favorite motard hero. It also helps that most of this fun is taking place at less than 30mph. The riding position helps, too, as the cushy seat and well-placed handlebar puts you in a very standard-like seating position. At just over 6-foot tall, I found this little bike to be the most spacious tiddler I have ridden in recent years.

Though it must be hard living under the vast shadow of the Honda Trail, the Yamaha Trailmaster 80 not only escapes the shadows, it jumps out into its own spotlight. It has that perfect combination of mid-Sixties styling, fantastic around-town usefulness, and an ability to sling a few rocks and mud on occasion. And it does it with a sophistication and sportiness that only Yamaha seems to be able to create. MC