By Tom White
By the mid-’70s, Yamaha was responding to market forces that indicated that the days of “polluting two-strokes” were limited. Yamaha decided to build a new four-stroke flagship for the dirt, one that would outclass the Honda XL350. The plan was to build a full-sized four-stroke single, similar to the British BSA singles in performance but with better reliability. It was code-named the YR400. Since Japan had a “tiered” driver’s license program that limited younger riders to 400cc, 400cc was the displacement for the Japanese market and 500cc was the displacement for the American market.
By late 1975, the YR400 had become the XT500, a new road/trail machine that was obviously influenced by the Honda XL. A few months later, Yamaha introduced the 1976 TT500. It was 15 pounds lighter and devoid of the XT’s road equipment. The TT looked like a motocrosser with number plates and a simplified but bulky exhaust system.
For my new company, White Brothers, the TT500 was like a shot of nitrous. My brother Dan and I had hoped for a more serious four-stroke race bike, and even fully modified, the TT500 never worked as well as the super-trick 1974 BSA B50 I had raced to a major four-stroke championship. However, the Yamaha TT500 was the right product at the right time. It sold well, and the White Brothers, Powroll and Pro-Tec sold a boatload of hop-up parts. We sold everything from 36mm Mikunis to high-compression pistons, to big-bore kits, to Terry fork kits, to Hallman Lundin frame kits.
The TT500 was a home run for Yamaha. In addition to the TT and XT500, Yamaha introduced the SR500—a street bike that was produced from 1978 to 1982. Yamaha reintroduced the SR500 as a 400 in Japan in 1994 and sold thousands. Yamaha’s biggest four-stroke success, the YZ400, would come along in 1998 and change motocross as we knew it.
1973 YAMAHA TT500 FACTS
WHAT THEY COST
Suggested retail was $1395. MXA’s pictured example was purchased from Rustan Motorcycle Sales in Midway City, California, then delivered to White Brothers where it had a WB001 Hi-Pipe and Pro-Tec Hi-Volume Oil Lines installed. It was ridden for 50 miles in the desert and then parked for 20 years. As far as my family, my employees and my brother and I are concerned, the TT500 put us on the map. It’s is priceless to me.
The TT500 was the only motocross four-stroke that Yamaha offered in 1976—although it was part of a larger family of single-cylinder 500s thaincluded the XT500 and SR500.
WHAT TO LOOK FOR
For the collector, the rules are “Stock is best” and “first-year models.” Good luck finding a stock one, as almost everybody modified the TTs. An original tank, pipe and carb would be desirable to any collector other than a White Brother.
Your friendly local Yamaha dealer might still have a decent parts supply (because of the variety of models using this engine). If not, contact www.thumperstuff.com, www.powroll.com or www.4strokesonly.com for aftermarket parts.