Yamaha were keen to claw back some of Eddie Lawson's deficit as the World Championship moved to the demanding Rijeka Autodrome. Although Spencer was back in practice, a further fall put him out of the 500 race and put Gardner under further pressure to deliver the goods alone. He was more than equal to the task, in spite of also crashing in training. Yamaha had been working hard to come up with more power to counteract the Honda and Lawson and Rob McElnea were getting more competitive. Randy Mamola and Ron Haslam also continued their good progress. The fierce heat called for edge-of-limit adhesion and riders cranked their machines to impossible angles - and frequently beyond!