Yoshimura history -29

A group photo taken right after it was confirmed that Yoshimura had won the 1989 TT-F1 title (a double championship along with their TT-F3 title win) at the MFJ Grand Prix at Tsukuba, the final round of the All Japan Road Race Championship. Diane and Doug Polen stand behind the TT-F1 machine, with Fujio, Yumiko and the staff. Oshima is standing at the far right.
Photo courtesy of Osamu Kidachi.

1989 Part 2, Polen Wins a Double Title in the All-Japan Series

1989 Polen Achieves the Historic Double-Title Victory

With the 1989 All-Japan series now in its summer break, the 12thSuzuka 8 Hours is just around the corner (final on July 30th). Yoshimura Suzuki prepared a two-bike team for the 8 Hours, with Kevin Schwantz and Doug Polen riding the #12, and Yukiya Oshima and Katsuro Takayoshi riding the #45. In 1989, the FIM Endurance Series was removed from the World Championship and returned to the World Cup status, with the Suzuka 8 Hours being the 2nd round of the series.

The color scheme of the two Yoshimura Suzuki GSX-R750s for the Suzuka 8 Hours was the conventional black/red combination for the #45 Oshima/Takayoshi bike, while the #12 Schwantz/Polen bike had an asymmetrical paint job, with Yoshimura’s black/red on the left side and Suzuki’s genuine blue/white on the right side. Was it a symbol of the fusion of Yoshimura and Suzuki, or was it because Schwantz was signed to Suzuki? Either way, it was an unusual color scheme.
Photo courtesy of Osamu Kidachi.

In the 4th qualifying round on Saturday, Polen set the 3rd fastest lap time overall, beating Schwantz, and secured 3rd position on the grid. The top two positions were only a small margin away from him, with #11 Mick Doohan (with Wayne Gardner on Honda RVF750) in pole position and #3 Wayne Rainey (with Kevin Magee on Yamaha YZF750).

The final race unfolded at an extraordinary pace, with times in the 2’15” bracket. After 3 hours, the top position was held by #11 Honda, with #3 Yamaha in 2nd and #12 Yoshimura Suzuki in 3rd. During the first stint, when Polen was riding the #12, there was a problem with the tires (a mistake in tire selection) and he had to make an unscheduled pit stop on Lap 15.

For Schwantz, the 1989 Suzuka 8 Hours turned out to be a series of bad luck, and a very frustrating weekend. In the qualifying round, the heavy rain made the track conditions unpredictable, and in the final race, he was plagued by fuel starvation and oil leaks, and was unable to show his true speed.
Photo courtesy of Osamu Kidachi.

#3 Yamaha blew oil at 130R on Lap 94 while Magee was riding. This made #12 Yoshimura Suzuki move up to 2nd place. Then on Lap 110, to everyone’s surprise, Schwantz was pushing the #12 on the back straight! It turned out that he had run out of gas, and it took him about 3 laps worth of time to get back to the pit. Once the #12 had finished refueling, the engine started up as if nothing had happened, and Schwantz was back in the race. Later, while Polen was riding, the bike ran out of fuel again and returned to the pit under its own momentum. The cause was that the choke on the carbs was left on (it may have been pulled by mistake during pit work). This made the air-fuel mixture too rich, causing the bike to run out of fuel and fail to complete the expected number of laps.

With just one hour left in the race, trouble strikes again for #12 Yoshimura Suzuki GSX-R750 (the tower in the background indicates 1 hour and 6 minutes remaining). Fujio and the team came up with a solution and the bike came into the pit at 18:28. It was an oil leak. They tried to fix it temporarily and get back out on the track, but the oil leak didn’t stop. It was found that the oil was leaking from one of the fittings on the sub oil-cooler (installed under the upper fairing for cooling the cylinder head). It took about 9 minutes to fix the problem.
Photo courtesy of Osamu Kidachi.

Further misfortune struck the #12. With about an hour remaining, one of the oil-cooler fittings broke, causing an oil leak. This ended any hope of a podium finish.

During this time, #11 Doohan, who has been in the lead, failed to overtake a backmarker (a lapped rider) and crashed out, retiring from the race. The Yamaha factory riders also retired due to machine trouble. Taking advantage of this, the #2 Honda Endurance Team took the lead and went on to win the race. The #45 Oshima/Takayoshi finished 5th, despite going off the track. The #12 Schwantz/Polen managed to finish the race in 8th place. Both pairs finished 5 laps behind the leaders, completing 197 laps.

#45 Yoshimura Suzuki GSX-R750, on Lap 134, the second lap after the rider change to Takayoshi, went off the track at Turn 1. The bike rolled over in the gravel and hit the crash pad. Fortunately, the bike was able to be repaired in the pit and he finished the race in 5th place. The cause of the crash was a gear disengagement.
Photo courtesy of Takao Isobe.

After the unlucky Suzuka 8 Hours, the Superbike World Championship Round 7 was held at Sugo on August 27th, before the opening of the All-Japan series. Polen aboard #48 took pole position in the qualifying round. Oshima aboard #47 crashed and decided not to race in the final. The final was a rain race. Polen showed his true ability by winning the Heat 1 and finishing 4th in the Heat 2.

Then the All-Japan Series began. At the 6th round of the TT-F1, held at Suzuka on September 10th, Polen aboard #32 qualified in 4th place and finished 2nd in the final race. He was ranked 2nd in the championship, just 5 points behind the leader.

In the 6th round of the TT-F3, held at Nishi-Sendai Highland on September 24th, #32 Polen took a pole-to-win victory, and in the championship, he maintained his lead with a 24-point advantage over #28 Nobuatsu Aoki in 2nd place.

The 7th round for both the TT-F1 and TT-F3 was the TBC Big Road Race on October 15th. First, in the TT-F3 race, which would decide the title, #32 Polen set a new all-time lap record to take pole position, despite only completing 6 laps in the first qualifying round and 5 laps in the second (in order to save energy due to the double entry). In the final race, he was in 5th place at the start due to the initial confusion, but he took the lead on the 4th lap and continued to pull away. He won the first title without waiting for the final race.

Also in the TT-F1, #32 Polen set an all-time lap record in the qualifying round and took pole position. In the final, he took the lead in the middle of the race and went on to win the race. He overtook #1 Shoji Miyazaki (Honda RVF750), who had won three races this season and was ranked at the top, and took a 6-point lead.

The final round was the MFJ Grand Prix on October 29th. In the TT-F3, where the title had already been decided, Polen qualified in 3rd place and finished 3rd in the final.

In the even more important TT-F1 race, #32 Polen broke the all-time lap record in the first qualifying round and went on to win pole position, but he made a mistake at the start of the crucial final race. In the confusion, he collided with a rival Honda RVF750, and was buried in around 15th place. At the top was #1 Miyazaki, and if Polen remained in 4th place or lower, Miyazaki would win the title for a second consecutive year. However, Miyazaki’s tires started to wear down, and he dropped all the way to 3rd place on Lap 13. Meanwhile, Polen gradually worked his way up the order and by Lap 21 he had moved up to 5th place. The race ended with Miyazaki in 3rd and Polen in 5th, and Polen was crowned champion with a slim 2-point lead over Miyazaki. This was the first time in history that a rider had won both the TT-F1 and TT-F3 titles. #4 Oshima finished 6th in the rankings.

After the 1989 season, a commemorative photo was taken in the United States to celebrate Polen’s double title victory in the All-Japan TT-F1 & TT-F3. The bike proudly wearing the #1 is a 1990 AMA Superbike spec GSX-R with a sub-oil cooler mounted on the side of the chassis for cooling the cylinder head. It was fitted with Dunlop tires, while the All-Japan spec bikes wore Michelins.
Photo courtesy of Yoshimura Archives.

In the 1989 AMA season, Yoshimura Suzuki rider #48 Jamie James achieved a double title victory in the Superbike and 750 Supersport (a production race with almost no modifications) categories. #22 Scott Russell finished 2nd in the Superbike rankings (Yoshimura riders finished 1st and 2nd) and 3rd in the 750 Supersport rankings. Although unlucky at the start of the season, in the end Yoshimura had achieved the best results in both Japan and the United States.

Stories and photos supplied by Yoshimura Japan / Osamu Kidachi / Takao Isobe
Written by Tomoya Ishibashi
Edited by Bike Bros Magazines
Published on August 14, 2024

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