Tim Bender and his Yamaha Vmax-4 Formula III Race Sled Tim Bender and his Yamaha Vmax-4 Formula III Race Sled
INSIDE THE HALL OF FAME: MAN AND MACHINE – By Greg Marier Photos: Wayne Davis, Rick Bates, Christer Dahl, Greg Marier The Man –... Tim Bender and his Yamaha Vmax-4 Formula III Race Sled


Photos: Wayne Davis, Rick Bates, Christer Dahl, Greg Marier

The Man – Tim Bender:

One of snowmobile racing’s most successful modified class drivers, Tim Bender raced Yamaha and Polaris snowmobiles at the start of the IFS development period in the ‘70s and became a legend as he displayed his amazing race sled design and driving talents aboard Yamaha snowmobiles through the mid-90s. Tim Bender was inducted into the Snowmobile Hall of Fame in 1999.

Tim Bender

Among his many Oval and SnoCross accomplishments are eleven overall points championships on Yamaha. While he posted wins in many types of snowmobile racing, Tim will always be remembered for his incredible four-year string of Formula III wins at Eagle River, dominating the class from 1985 to 1988, and his seven 1992 FIII-class victories on the Vmax-4 FIII race sled featured here.

The Machine – 1992 Yamaha Vmax-4 Formula III race sled:

New for 1992, the Vmax-4 was Yamaha’s flagship model featuring a 750cc 4-cylinder 2-stroke engine. To promote Yamaha’s performance image, the Yamaha Bender Race Team was formed to race the Vmax-4. This FIII sled was raced by Tim Bender with the engine technology developed by Yamaha and the chassis, suspension and clutching modifications developed through Bender Racing.

OK Tim, it’s the 1990s, you have been very competitive in FIII with the Yamaha Exciter and the opportunity came to build the Vmax-4 into a FIII race sled – How did it happen?

In 1991, a year before the Vmax-4 was released, Yamaha contracted me to help evaluate the potential of the Vmax-4 in FIII oval racing. Yamaha Japan was to build the race-spec motor and I was to help complete the sled assembly. When I was fitting the Factory-built pipes into the Vmax-4 at Yamaha R&D Minnesota, I met Rick Bates for the first time. We kind of befriended each other there and later on we would start to work together on the full-fledged race sled. When this test sled was completed, Jim Kedinger and I went to do the preliminary evaluation in Alaska. The first time we ran that sled it sounded cool as hell because it was a 90-degree firing 4-cylinder 2-stroke – as you can imagine, it sounded pretty good. Unfortunately, on the first wide open throttle run it spun the clutch reduction gear, which threw the crankshaft out of phase and that was the end of our testing. However, one good thing to come out of that trip was that Jim asked if Bender Racing would be interested in becoming the official aftermarket performance parts company for Yamaha snowmobiles and, of course, I said we were. We would compete as the Yamaha Bender Race team in FIII and major Grass Drags events plus represent Yamaha at these events by selling parts, t-shirts and hats out of our trailer. It was a great opportunity for us, both as a company and as a race team.

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To go from a spun gear in Alaska to being competitive in FIII – How did that development program happen?

When Yamaha took the engine back to Japan, it was determined the race-spec engine should fire at 180-degrees (rather than 90-degrees), so 1 & 4 and 2 & 3 cylinders would fire together – this layout was basically two twin-cylinder engines connected through a gear reduction to the drive clutch. The gearing reduced the clutch speed by 16%, (crankshaft at 9800, clutch at 8300 rpms) which reduced belt speed and drive clutch windage loss. In addition, the engine did not use a typical flywheel, but ran an inter-rotor total-loss ignition system with a battery for power. The rotor weighed 8 oz and the engine would rev quick.

Yamaha wanted to confirm the reliability of the 180-degree firing set-up at high power levels, so they ran a dyno durability test. – They ran the FIII-spec motor for 6 hours at wide open throttle! It was a crazy amount of testing. The engine produced 178 hp and, at that power level, the 180-degree firing set-up was proven to be strong. The only engine change we made was to take out one layer of head gasket thickness to increase the compression. We ran it on high-octane fuel and entered the race season at 187 hp.

Tim Bender Yamaha Vmax-4

We felt we would have plenty of straightaway speed so the team focused the chassis build on handling. We did everything the rules allowed to get the weight low and to the left. The engine was dropped as low as we could, handlebars modified for oval racing, chassis stiffened up with an over-the-engine tube frame, pumped up the brakes, lowered and increased the stance of the front suspension and built the stock rear suspension into a FIII suspension. We also relocated the gas tank under the secondary clutch, put the lube tank on the left-hand side of the running board, moved the heat exchangers to the left-hand side of the tunnel and moved the radiator as low as we could. We even offset the track in the wide Vmax-4 tunnel as far as possible to the right to counter cornering forces. One trick we continued from our Exciter FIII days – we had the foot lever on it so that after the holeshot we could pull it up so that a shorter limiter strap length would pull the front of the rail up off the ice so you just had a small stud contact patch in the back. When I look at the sled today, the workmanship was beautiful. Rick Bates, the team’s crew chief, fabricated these changes and he was an artist.

Tim Bender Yamaha Vmax-4
How many were built and who were some of the people behind the development?

That sled at the Hall of Fame was one of three sleds built for the 1991-1992 race season. From the Yamaha side, Jim Kedinger was the Snowmobile Racing Manager and our Factory engineering contacts were Sasaki san, Suzuki san and Imamura san. From our side, I asked Rick Bates to come to my shop in New York and he agreed. We hired Mike Sackett as a co-driver and Bruce Schrader, my brother Bob, Dave Mitchell, Chris O’Brian, Denny Newell, Justin Fuller and Dave Curran joined in. We even had Christer Dahl and Michael Nordstrom come over from Sweden to help with the build. At the track, Mike had a couple of guys that helped too, but unfortunately I don’t recall their names.

Tim Bender Yamaha Vmax-4 Formula III racing
Now the sleds are built and the team is in place – How competitive was the sled at the first race?

It was very competitive. The season opener was at Brainerd, Minnesota with FIII qualifying and finals set for both Saturday and Sunday. On Saturday, a full day of racing made the track rougher than hell – it got too rough to race the FIII final, so they iced it down that night and ran the Saturday FIII final on Sunday morning. The track was fairly smooth and I ended up winning that one. Later that same day, we were racing the Sunday Formula III – and I didn’t win that one. Our holeshot wasn’t very good yet and coming from the back on a rough track was tough. I couldn’t see through the snow dust enough to miss the holes, so I couldn’t go wide open up to the corners like I was used to. Remember, this was the first weekend racing the Vmax-4. In the past, I had to really charge hard into the corners on my FIII Exciter to win but now, charging full throttle through snow dust into a rough corner was quite a challenge.

Tim Bender Yamaha Vmax-4

I remember after that Sunday FIII race, as I was taking my leathers off in the trailer, thinking to myself, ‘This sled is so damn fast, there is no way in hell that I’m going to be alive at the end of the season’. There was an interview with Kenny Roberts, the Yamaha motorcycle racer who raced a TZ750-powered two-stroke race bike on the dirt, and he said “Yamaha doesn’t pay me enough to ride this thing.” I thought to myself ‘If Yamaha didn’t pay him enough to ride that, they sure aren’t paying me enough to ride this.’

Tim Bender Yamaha Vmax-4 Formula III
Wow – so why did you get back on it?

I was a third-generation racer. My grandfather built race cars, my father raced cars and my brother and I raced sleds together since the ‘70’s. I knew the risk was there, but I just wanted to win so bad I considered the danger as just part of the deal. The last thing I was going to do was to complain that we finally had a Yamaha engine that had some power! We had been racing the Exciter 570 in F-III and winning with it, but it as was way under-powered – but we won using better corner speed. Now we had 187 hp in the Vmax-4, so we had to control all that power through the corners. We also got very little time on the sled before the first race and, in New York, preseason testing was very scarce. We would drive through the mid-west and see a bare, frozen lake along the road and pull over. We’d unload our sleds and make some passes until somebody complained about the noise – I still get excited when I see a bare lake! The more times I rode the sled, the more we got it dialed in. I also stepped up my training to get in better shape. You have to remember I was running Bender Racing at the busiest time of the year plus I was helping Rick a little to build the sleds so I didn’t have the time to devote to the gym, but I realized I had to do it.

Tim Bender Yamaha Vmax-4 Formula III racing
What were the major takeaways from that first race weekend?

Most importantly, we saw that we worked well together as a team. We learned we could win on smooth tracks, that we had plenty of speed and there weren’t any major mechanical issues. Sorting out any ‘teething issues’ on a new sled with a new team can be a challenge – and we had twice as much work in order to keep two guys competitive. We had a good plan – both sleds were identical, other than we ran a Polaris secondary on one and a Yamaha secondary on the other because we didn’t have enough cams to run them both at the same spec. Every adjustment we made on mine we made on Mike’s. He was a good rider but didn’t have a lot of time on the sled, so if I felt we needed more spring on the right-side front, we would change it on both sleds and usually Mike would come back and confirm what I had felt.

Tim Bender Yamaha Vmax-4
Rick Bates and Dave Curran

The major issue that weekend was getting the holeshot. We just couldn’t get all that power hooked up. We started out with a 300-stud set-up and by the Sunday final, we had close to 500 studs on the track! It was crazy how much iron we had on the track trying to get it to hook up.

One thing we had that no one else was really using was data acquisition (Bender Racing was the sole RacePak supplier for snowmobiles). Instead of a laptop, which really weren’t around at the time, we had a printer and we would live or die by the printout. From the data, we could tell we were still spinning halfway down the straightaway at Brainerd. Our go-to solution at the time was to drill more holes in the track and add more studs.

Tim Bender Yamaha Vmax-4 Formula III
After the Brainerd race, how did the rest of the season go?

By about halfway thru the season we were starting to get the rear suspension dialed in so we went faster and faster. We could trip the radar at 110 mph on a half mile oval, which was about 8 mph faster than anything else out there. By Owen Sound, we were really fast. We went to start my sled for the final and it wouldn’t start. It had no spark – it just wouldn’t spark. Mike’s Vmax-4 didn’t have an issue and he ended up winning that one. After the race, my sled started right up. We tried a lot of different stuff to try to figure out why mine lost spark when Mike’s ran fine but, at that time, we never found a reason.

Tim Bender Yamaha Vmax-4 Formula III

We went to Ashland, Wisconsin – I won there, but we got disqualified for being too light. That’s right – too light with a Vmax-4! 475 lbs was the minimum weight and the sled was 485 lbs on our scales in the trailer so we felt we were plenty heavy. If I had any idea it was close, I wouldn’t have burnt up that fuel taking the checkered flag around the track or would’ve drug my feet to throw snow onto the suspension. Bill Rader was the tech guy, who we later became good friends with (at Polaris Racing). He was rather hard-headed (and I was hard-headed) so we butted heads just a little bit there. We hooked up my scales and weighed it right in front of him. It was over 480 lbs on my scales and all he said was ‘My (His) scale is the only one that counts’. So, we got disqualified.

Tim Bender Yamaha Vmax-4 Formula III

Eagle River was the next race and the sled had been running really well. We were pre-race testing our zero-to-750 feet speed on a local lake with the radar gun. As I was going 100 mph at the end of the run, the track came out the back of the sled – and I kept going with no track and no brakes! The sled swerved to the left, went to the right, I caught it a couple of times but the third time I couldn’t catch it and it went cartwheeling down the ice. Parts were flying everywhere; it was a mess. So, the team was thrashing back at the truck to get that thing put together before the race weekend started.

One of the things that we didn’t catch was that we had bent the crossmember, which put some positive camber into the left-hand ski. (Negative camber is top in; Positive camber is top out). We never ran positive camber on the left ski because it would cause darting. In the first practice run, sled was really snaky – we discovered we had a problem and there wasn’t much time to fix it.

Tim Bender Yamaha Vmax-4 Formula III

For handling adjustments, we had a system to easily make ski camber changes. We had ski mounts with the ski bolt hole welded up and re-machined to give various camber angles. We would adjust the ski camber depending on ice conditions. On soft ice the carbide hooks up better so if you ran too much right-ski negative camber, the sled would tip up. With less negative camber, as the sled started tipping up, the carbide would break loose and the sled would drop back down. We would run as much right ski camber as we could and still stay relatively flat.

Tim Bender Yamaha Vmax-4 Formula III racing

Now back to Eagle River. Before we went out for time trials, we adjusted for the bent crossmember by putting a 2-degree negative camber ski mount, but what was installed was a 2-degree positive set-up by mistake. When I went to qualify, the thing was completely out of control. I still set fast time in the first session, but the sled was about to buck me off everywhere it could. We had to get this fixed before the qualifying heats started so we sat out the second qualifier time session in order to regroup.

Tim Bender Yamaha Vmax-4 Formula III racing

The solution was to check the camber on the ski itself, which is what we should have done in the first place. We got the left-ski zeroed and set the right-ski at negative 2 degrees. With the handling fixed, we were very fast and won all of the qualifiers. In the final, we got the holeshot and were pulling away, but half through the race the engine shut off. It was the same thing that happened at Owen Sound. I coasted to a stop, grabbed the recoil and pulled it over (and over!) but it wouldn’t start. At Eagle River, the biggest race of the season, and I was watching the other racers go by. I think that Mike Sackett finished second and Guy Useldinger won it.

It was the day after I got back from Eagle River and the engineer that dynoed the engine in Japan was at my shop in New York to figure out what the hell was going on with that ignition. It was strange it happened on my sled but never on Mike’s. Yamaha was convinced that we had not followed the wiring diagram and wired it wrong. Come to find out it ended up being the wiring diagram that was incorrect. He unplugged one wire and plugged in another like it was run on the Yamaha dyno – and that fixed it. Once we switched that wire, we never had an engine miss another beat – that was a real kick.

Tim Bender Yamaha Vmax-4 Formula III racing

After solving the wiring issue, the next concern was track life. To get the traction we needed, we always ran as many stud ‘scratch lines’ that we could, and eventually adding all those studs had cut every cord in the track. We found that the track would eventually fail if we ran it too long. At Valcourt, Mike Sackett was running in practice at 107 mph on the straightaway and the track came out the back of his sled. Up in the close-off, there was hidden damage to the rivet heads that held the lower steering post mount to the bulkhead. In our haste to change tracks, we didn’t see that – So when Mike was racing later in the day he went into the corner at full speed, the steering post pulled the clawed-off rivets through the mount and he lost the steering. He bailed off the sled, the sled went into the hay bales first and he hit the running board with his legs. It was a tough deal. He was in the hospital in Quebec for quite a while after that, but he eventually did get to go home to heal up.

The last race of the season was the World Series in Antigo, Wisconsin. To fill in for Mike, we got Rick Haag to ride the sled. The sled was so fast, so dialed in by then that you just couldn’t believe just how dominant it was. We won by half a lap. For the full season, Yamaha Bender Racing won eight FIII finals on the Vmax-4. Mike won one and I won seven.

Tim Bender Yamaha Vmax-4 Formula III racing
What a season! What were the plans for the next year?

We planned to keep on winning, but there was no doubt that the muscle sled-based FIII race sleds were very fast and only a small group of racers – racers like the Houle brothers, Useldinger, Appolson, Sturgeon, Sackett, Haag – could handle them. To slow the sleds down, the Manufacturers voted to change the ISR race rules to 600cc. At the time, Yamaha was not a member of the ISR so they didn’t have a vote. While the 4-cylinder Vmax-4 was deemed too fast for future FIII racing, Bender Racing kept racing it on the grass drag circuit. Working with Jim Czekala at C&H/Dynotech, we got the 800cc 180-degree Vmax-4 engine producing over 220 hp. That engine could make a lot of power!

This all happened almost 30 years ago. Looking back, what do you think about that race sled now?

When I look back on the success we had as a team, the power we brought to the track and considering the engineering and the workmanship that went into that sled – it’s just amazing. The guys all worked hard to pull it together, the motor was way ahead of its time and Rick’s fabrication skills are evident – even the Yamaha-designed paint job was cool! Probably the most copied sled graphics ever!

Tim Bender Yamaha Vmax-4 Formula III racing
Great insight on an iconic race sled! Thanks. What have you been doing after retiring from driving race sleds?

After a stint in car racing, I wanted to spend more time with my son Brett. He started racing SnoCross and next thing I knew (thanks to some prodding from Rick Bates), I was building Mods, running a SnoCross team and Brett was racing for us. I’m now Team Manager for Hentges Racing race team with Kody Kamm and Osker Norum as our riders. Team owner Nate Hentges and his family have always been there for me. Some team highlights include when our riders TJ Gulla, Brett Bender and Levi LaVallee placed 1-2-3 in the 2009 Pro Open points championship, and in 2017 Kody won the ISOC championship and Peter Narsa won the Gold at the X Games!

Tim Bender Yamaha Vmax-4 Formula III racing

In addition to the Hentges Team Manager duties, I also do the team’s R&D stuff during the summer. When we were running mod sleds, we would do all of the engine development, pipes and we actually had a power advantage at that time. Now we are racing basically stock sleds with some areas open to making improvements. We can make changes with the brakes, the silencer (as long as it is commercially available) and the suspension – you can’t change the geometry but you can work with the springs and the shocks, so there is a lot that you can do there. Basically, we do a lot of shock testing with Walker Evans. They are amazing! Walker Evans has a very high-end dyno that can cycle a shock at a couple of hundred inches per second, and I have a shock dyno in the Hentges team race truck that goes to forty inches per second. Polaris Race Coordinator Ben Hayes, Team Engineer Sean Ray, mechanics Levi Ensrud, Dan Giboo, Walker’s Bob Karhs and our riders all work closely with each other on finding the best shock and spring specs.

I also work with Rick Bates, Ben Hayes and Polaris Race Manager Tom Rager Jr. a little on testing new stuff on the next year’s race sled. Rick Bates has been doing Polaris race sled development work for probably 20 years now, so it’s funny on how things happen – When it comes to snowmobile racing, it’s a small world.

Outside of SnoCross racing, I saw a custom 1940 Ford pickup in a magazine and fell in love with it, just the flow of it with the big fenders, I just really loved the look, so I’m in the middle of building a ‘40 Ford pickup truck hot rod with a LS engine in it, building the chassis, putting in an air suspension – the works. The problem with the ‘40 Ford is that there are no re-pop parts for them, so now I’m working on rebuilding the right rear fender using my English wheel.

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Snowmobile Hall of Fame

Visit the Snowmobile Hall of Fame in St. Germain, Wisconsin to learn more about the heroes of our sport and view the many historic snowmobiles and racing memorabilia on display at the museum. Check them out at www.SnowmobileHallOfFame.com or on Facebook at “The Snowmobile Hall of Fame”

Snowmobile Racing Hall of Fame
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TIm Bender Vmax-4
Tim Bender Vmax-4 Formula III
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