1973 Isle of Man TT

The 1973 Isle of Man TT motorcycle road races were held between 2-8 June 1973 on the 37-mile Snaefell Mountain Course. It was the fifth round of the 1973 FIM Motorcycle Grand Prix World Championship (now MotoGP). In 1973, most of the World Championship contenders were absent from the Isle of Man TT races with the exception of Jack Findlay and the sidecar contenders.^[1] The rest joined the reigning 500cc World Champion Giacomo Agostini in boycotting the Isle of Man TT event over safety concerns, despite extensive resurfacing of the circuit.^[1] The resurfacing allowed an increasing number of competitors to surpass the prestigious 100 mph average lap time.^[1]

The racing began on Saturday, 2 June with Production Class racing that consisted of 750, 500 and 250cc machines as well as the 750cc Sidecar Class.^[2] Peter Williams led the 750 class on the John Player Norton by half a minute when a gearbox problem forced him to abandon the race allowing Tony Jefferies to take victory riding a Triumph Trident motorcycle known as Slippery Sam.^[1] The victory marked the third of five consecutive Isle of Man TT victories for Slippery Sam.^[3][4] Stan Woods (Suzuki) led the 500 class by half a minute, when on the last lap his engine began to misfire, allowing Bill Smith (Honda) to claim the victory.^[1] Charlie Williams (Yamaha) won the 250 class.^[1] 250 Class competitor John Clarke (Suzuki) was killed in an accident at Union Mills on the first lap.^[1] World Champion Klaus Enders and Ralf Engelhardt won the 750 Sidecar Class ahead of his BMW teammates Siegfried Schauzu and Wolfgang Kalauch in second place.^[1]

On Monday, 4 June, Charlie Williams rode a Yamaha TZ 250 to win the Lightweight TT while in the 500cc Sidecar TT, Enders set a new lap record and finished the race over 2 minutes ahead of his BMW teammate Schauzu.^[1] Tony Rutter won the Junior TT on 6 June in a class dominated by the newly released Yamaha TZ 350.^[1] 38-year-old Tommy Robb (Yamaha) won the Ultra-Lightweight TT later that same day, marking the first TT victory of his career which began at the 1958 Isle of Man TT.^[5]

The final events of the week were the Formula 750cc TT and the Senior TT held on Friday 8 June. After his abandonment earlier in the week, Peter Williams redeemed himself by setting the second fastest-ever lap of the mountain course at 107.27mph and won the Formula 750cc TT ahead of his John Player Norton teammate Mick Grant.^[6] Helmut Dähne scored an impressive ninth place riding a shaft driven BMW R75/5 better known for its long distance touring capabilities.^[1] The final race of the week was the Senior TT where 38-year-old veteran Jack Findlay rode a Suzuki TR500 to win the first TT race of his career after Mick Grant (Yamaha) crashed on an oil slick while leading the race at Ramsey Square on the third lap.^[1] Peter Williams rode an underpowered but agile single cylinder Matchless G50 prepared by Tom Arter to score an impressive second place result.^[7] Williams' average of 100.62 mph was 2.6 seconds quicker than Mike Hailwood's winning speed in 1961 on a Norton Manx, making them the only two competitors at that point in time to have averaged over 100 mph on a single cylinder machine in the Senior TT.^[1]