Quote Originally Posted by Fast Fred View Post
the exhaust on the 60DES was separate from each other, twin cow bell. held all 750cc records.at about 5500rpms about 40hp slams into the power band.
Yamaha SUPERJET 701 TWIN
comes stock with individual tuners similar to the 60 twin, makes 73 hp , with twin 38mm carbs and several other similarities to the 45.
Difference is in the late nineties RD Performance figured out a exhaust the worked from 3,500 rpms up. I was fortunate enough to talk to the engine guru there several times. He said they filled up a 40ft trailer with test pipes. They end result was a pipe that bumped a stock 73 hp Yamaha up to 100hp. In 1999 and 2,000 RD dominated every heat of the Worlds with that pipe. On a ported Yamaha they sell the pipe in a kit and gaurentee 140 hp from 7,400 to 7,800 along with arm wrenching acceleration. They said they could make more power but the drivers want acceleration. I have one of the pipes never used it or RD race porting specs. Just running rec specs. Stock Super Jet Exhaust opens at 89 deg ATDC Transfers open at 120/118 deg ATDC .