We pushed on with the torture with another 30-hour-plus stint out in the desert. We thought we'd see how the bike would like wide-open running, nearly 1200 miles of it by the time we were through. We laid out a 55-mile loop that took just over an hour to ride, and the only change to the bike was a bump in the gearing with a one-tooth-larger countershaft sprocket. The bike was pinned for most of the time, and all we did was one oil change halfway through the night. At the end of it we thought that the bike would feel at least a little bit tired. We were wrong. It was still running as good as if not better than when we first got it. Just to be sure, we took it by Yamaha where it ran it on the same dyno it uses to break in the bikes. The technicians have a record of this very bike, and after 125 hours on the run timer it had only lost 0.5 horsepower compared to when it was fresh pumping out 31.9 horsepower. Not bad considering we felt we were abusing it. The valves still checked out in spec and everything looked brand-new on the inside. The outside was another story.
From here on out we sent the bike out on every trail ride we could get it invited on. Everything from family putt-putts to hard-core EnduroCross training. It survived everything we could throw at it, and the only casualties were the radiators which were bent so bad it was too late for help in the form of a guard. We even had to have the tabs for the shrouds welded back on.
Our last hurrah for the bike was a final 24-hour at Glen Helen. We passed the bike to Tyler Ruiz and his team of riders, who easily finished the event though they had a clutch abuser on the team, going through one and finishing on another nearly smoked clutch.
With 202 hours showing on the hourmeter (and we know it wasn't working for a few hours as well), we took the bike to the photo studio and tore into it. Aside from a lot of bumps and bruises, like a smashed oil tank, an insert in the gas tank in which the shroud bolt had become stuck and lower frame rails that looked like they'd been dragged down a gravel road, everything was tight. The motor was in shipshape except for the cavity where the oil pickup resides, and it showed that something metal had gone though the motor. We'd never noticed anything in riding it or in changing the oil and the oil filter, but the pickup screen had been doing its job. There were no signs of damage anyplace else in the engine, and we imagine it was a piece of the clutch damping system or some debris from one of the clutch changes. The piston looked like it could go another 200 hours and every bearing surface inspected was perfect. The cylinder did show some wear but checked in spec with the ring end gap still having 0.004 inch before it went out of the published (conservative) range. The valves hardly showed any signs of wear, and the fact that they never needed any adjustments would back that up. We had this bike on a diet of Yamalube 20W-50 and running Rock Oil SWAFF on the air filter. If this is the result, we recommend this stuff. Again, it's a testament to keeping the air filter clean and installed properly with fresh engine oil.
Running Tally
Hours on Bike: 202+
Maintenance and Repairs: $634.64 (notincluding tires)
Fork service: $85
Fork seals: $20
Shock service: $95
Valving: $55
Shock oil: $15
Weld radiator: $15
4 oil changes and 1 filter
Oil filter: $11.95
Yamaha 20W-50 oil: $4.88 ea.
Oil tank: $183.94
Clutch: $162