Two-Stroke Scramble: 1968 Yamaha Big Bear

When Al Roller came across this 1968 Yamaha Big Bear YDS-3C, he tore it down to the frame and restored it to perfection.
By Greg Williams
March/April 2014
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A 1968 Yamaha YDS-3C Big Bear.
Photo by Jeff Barger
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1968 Yamaha YDS-3C Big Bear
Claimed Power:
28hp @ 8,000rpm
Top Speed: 85mph (period test)
Engine: 246cc air-cooled 2-stroke parallel twin, 56mm x 50mm
Weight (wet): 349lb (159kg)
Fuel capacity/MPG: 4.1gal (15.5ltr)/75mpg (period test)
Price then/now: $690 (1965)/$3,000-$5,000

Yamaha motorcycles have indelibly marked Al Roller. They had to. He grew up just 100 yards from the local Yamaha of Port Washington, Wis., dealership and his family — mom, dad, two sisters and brother — all rode trail bikes bearing the tuning fork badge. And — how cool is this? — Allen’s mom used to take him to school two-up on a 1973 Yamaha AT125.

“Motorcycling was a family affair,” Al explains. Born in 1969, Al was 8 when he got his first Yamaha, a 1976 GT80. Although many other Yamahas surrounded Al, the model he clearly remembers the most is the 250cc Yamaha Big Bear, a motorcycle that had very few changes to its architecture during a short production run from 1965 to 1968. “The older guys used to ride Big Bears around the dealership, and you knew they were special because they were loud and fast,” Al says.

Al went on to compete in motocross and stand-up jet ski racing, and his first street bike was a 1984 Yamaha FJ600. Motorcycles remain almost a singular passion for Al, now a toolmaker working at Strohwig Industries in Richfield, Wis. His family continues to ride, including his wife, Erica, and their three sons. One day, the boys will likely inherit Dad’s collection of vintage Yamahas, which continues to grow as Al can fund the purchases. Included among several other Yamahas in the garage are a 1975 RD250, a 1972 U7E (his mom’s first bike, and already something of a family heirloom), and a 1975 DT175 he just picked up.

A favorite discovered

Al’s favorite Yamaha might just be this 1968 Yamaha YDS-3C Big Bear Scrambler. Back in 2000, Al was at a local motorcycle accessory shop buying a helmet. That was when he noticed a “For Sale” ad posted to the bulletin board: “Big Bear Scrambler 250 Twin, $450 OBO,” it read. There were a couple of pull-tabs with the seller’s number, and Al followed up.

Al’s older brother Dan is an accomplished rider and worked for a time at the local Yamaha dealership. Al appreciates Dan’s knowledge of the brand. “My brother and I went to look the next day, and when I asked him if he thought it was worth it, my brother said, ‘If you don’t buy it, I will,’” Al recalls. “I offered him $425 and he accepted, so it came home with me.”

Although totally complete, the Big Bear looked like it had been sitting outside leaning up against a fence or outbuilding. The left side was sun faded, while the right side was in relatively good condition. Al considered the motorcycle to be a project he would eventually get to, but it was titled, registered and insured, and it ran. “It didn’t have baffles in it, and I’d ride it occasionally,” Al says. “It sounded very crisp and assertive.”

And it should. The YDS-3C Big Bear Scrambler evolved from the legacy of Yamaha’s twin-cylinder 2-stroke supremacy. In 1953, Genichi Kawakami was the president of Nippon Gakki in Japan. The company produced musical instruments, and there was extra capacity for another line of products. Kawakami settled on motorcycles, and the first bike, a 125cc 2-stroke single dubbed the YA-1, bore the name of one of Nippon Gakki’s founders, Torakusu Yamaha. The YA-1 signaled the founding of Yamaha Motor Co., Ltd., in 1955 and the construction of Yamaha’s first factory that same year.

Nicknamed the Red Dragonfly, the YA-1 was principally a copy of the 1939 German DKW RT125 featuring a unit-construction 2-stroke single with an aluminum case and cylinder head, and designed by Hermann Weber. Plans for the DKW single were liberated postwar as a process of reparations, and many other manufacturers, including BSA (Bantam) and Harley-Davidson (Hummer), built DKW-like singles. So did Yamaha.

The Yamaha Big Bear

In 1957, Yamaha yet again copied a German design — the Adler MB250 — to create the 250cc twin-cylinder YD-1. Soon, the company had a successful formula with its 2-stroke twins, and the YD series prospered with the YD-3 street bike and the sportier YDS-2 in 1962.

Yamaha’s big news for 1964 was Autolube, a major advancement in oil injection technology. Previously, 2-stroke engines required pre-mixing oil with the gasoline — often a gas tank cap had an oil cup built into the underside for “accurate” lube measurement in whatever ratio was required. The 125cc Francis-Barnett Merlin, for example, with its Villiers 2-stroke, featured a built-in gas cap measure to aid meeting its required fuel/oil mixture of approximately 20:1.

Autolube first appeared on the 1964 246cc YDS-3 twin, a 2-stroke road-going sportster rated at 27 horsepower at 7,500rpm. Equipped with a 5-speed gearbox, double downtube frame and low-level exhaust, the 335-pound YDS-3 reached 76mph in 16.6 seconds in the standing quarter mile, as tested in the July 1964 issue of Cycle World.

With the road-going YDS-3 gaining acclaim, in 1965 Yamaha introduced the YDS-3C Big Bear Scrambler. A major event on the racing calendar, the Big Bear Run pitted man and machine against the extreme conditions of the Mojave Desert and the San Bernardino Mountains. Yet Yamaha had never won a Big Bear, and some wondered what right the company had borrowing the name.

Regardless, based on the YDS-3’s 246cc twin-cylinder piston-port 2-stroke engine and frame, the 250cc Big Bear Scrambler was designed for street and trail. The Big Bear wore a high-level exhaust system, with one pipe for each cylinder. Shielded by elaborate chrome-plated protectors, the pipes featured large, 18-inch long baffles, each one weighing 3 pounds! The baffles were removable after simply unscrewing an end cap. For their size, the baffles only slightly quelled noise, but without them, the din was shattering.

A cross-braced offroad handlebar sat atop a purposeful fork with exposed chrome springs, and a period Cycle test reported the suspension — both fore and aft — was stiffer than that found on a street-only Yamaha. An under-frame rock guard protected the engine, and the Big Bear weighed in at 350 pounds.

“It’s a stormer!” Cycle editors proclaimed in their July 1965 issue. “The Big Bear is definitely one of the hottest 250 street machines we have tested. But the Yamaha’s speed characteristics are individualistic in that there is a directly noticeable rpm range where the bike really ‘turns on.’ Above 4,500 rpm, the Big Bear twin seems to ‘explode’ with power.”

Popular in their time and highly sought-after today, the 250cc Big Bear stayed in production with only mild updating through the 1968 model year. With offroad bikes getting more popular and more specialized, that same year Yamaha introduced the revolutionary 250cc DT1. The DT1 would return in 1969, but the Big Bear’s run was over.

Restoration time

In 2006, Al decided it was time to pay some attention to his YDS-3C. Pleased that his Big Bear ran and shifted cleanly through the gears, at first he planned only to clean and detail a few pieces, but after removing the gas tank, airbox, oil injector tank and the seat, he didn’t stop. Soon, the bike was completely apart, its individual pieces bagged and tagged.

“My twin boys were born right around this time, and that financially strapped me,” Al says. “I had some time, but no money to really spend on the bike.” As a toolmaker, at work Al has access to sandblast cabinets, lathes and mills. He began cleaning and detailing all of the various subassemblies — whatever he could do himself without spending much money.

Al began by media blasting the frame, swingarm, engine guard and stands, followed by a layer of black powder coat paint. The fork required new tubes, as the originals were rust pitted. Those came from Speed & Sport Inc. in Bloomsburg, Pa. Yamaha of Port Washington — family owned since 1967 — provided new points and condensers, and the fork seals. Other new-old-stock parts were found on eBay, but Al didn’t need much more.

As found, the Yamaha was surprisingly complete, and unlike many other restoration projects where rubber bits are perished and control cables are shot, Al got lucky. He cleaned and detailed the cables, and resourcefully restored a single damaged footrest rubber. An end had been ground off one of the passenger covers, so Al machined an inner blank. With the blank pushed inside the rubber, he sprayed the outside with black undercoating, and the deceptive repair has held — more importantly, Al says, is that no one has ever noticed, either.

Al had the cylinders bored to the first oversize, fitting new pistons and rings in the freshly painted jugs. He blasted the heads and protected them with a high-temperature clear coat. The cases weren’t split, but Al detailed the raw aluminum and then spray painted the outer covers silver. Apart from sandblasting the clutch plates and rebuilding the dual 26mm Mikuni carbs, the engine didn’t require any other attention.

Al didn’t completely disassemble the wheels, but left them together to clean around the spokes and hubs. A little cash was offered to a tool polisher at work to restore the luster to the brake plates and the top fork triple tree. The brake shoes were in good condition, as were the hub bearings. “I’ve probably got 20 hours per hub, though, in steel wool and elbow grease,” Al says. Rims still wear their Yamaha chrome, and Al installed new tires.

More parts would have been re-chromed, but Al’s budget only allowed him to plate the fork springs and covers, top stanchion and triple clamp nuts, rear shock springs, the left exhaust pipe and both heat shields, and the rear pipe struts. The fenders are original and, thankfully, straight, and the previous owner had recovered the seat. Although Al was offered a brand new speedometer/tachometer assembly as a replacement, he opted to keep the original unit. “The old one works well, indicates the original miles and shows the bike is 46 years old,” Al says.

Al coated the inside of the gas tank before sending it and the oil tank, side cover, headlight and fork ears for painting. If he saved money on other parts of the rebuild, this is where he dropped some dough — and the paint is where he deviated slightly from original. Overall the red/white paint scheme is correct. The candy-apple burgundy is matched as close to factory as possible, but instead of the plain white Yamaha used, Al opted for a pearl white. Matt Pape at Pape’s Chop & Drop Shop in Grafton, Wis., applied the paint.

After a few minor wiring repairs, Al reassembled the Big Bear, adding an aftermarket mirror to make the machine street legal. He was done and riding the bike by mid-summer 2007. “Two kicks and it’s running,” Al says, adding that it’s a great machine to ride. “My daily rider is a 150 horsepower liter bike. When I’m riding the Big Bear and wind it out, it feels like I’m doing 150mph, and it’s really exciting and exhilarating. I get a big grin riding something this old, with only 28 horsepower as opposed to the 150 of my modern bike.”

Al’s Big Bear turned 5,000 miles at the 4th Annual Road America Motorcycle Classic show in June 2013. While there, he was encouraged to display the Big Bear in the annual Motorcycle Classics Vintage Bike Show and was stunned to be awarded Best Restored Japanese. It was fitting recognition for a lifetime steeped in the brand. MC


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Post a comment below.

 

TONYC
3/6/2014 11:40:51 AM
My first real bike was Big Bear scrambler, so this brings back a lot of memories for me. All the cool kids in high school were riding Honda 305 scramblers. I wanted to ride, but was never one to follow the crowd, so I went for a Yamaha 305. I had no idea what 2-stroke meant(or 4-stroke, for that matter), so was rather surprised when it first fired up. Sure sounded odd. But I quickly learned that not only was it faster than the 305 Hondas, it was also faster than the newer CB350 Hondas that had just come out. I seem to recall the tank sides being chrome, rather than the white. And the tank had a large chrome acorn nut on top, which served as a vent. Same exhaust pipes as are on the this 250, and yes it's LOUD with the baffles removed. My 60 year old ears are now paying the price for my then-16 year old experiments in exhaust tuning. Thanks for the memories.








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