Four-strokes continue to develop on the forefront of dirt bike technology, and it’s safe to say, generally speaking, that the buying public and media have been sucked into the thunderous vortex. That isn’t to imply that there’s no interest in two-strokes, nor that they are competitive. There are plenty of holdouts and die-hard premix riders (you all remind me every time we post a new four-stroke test). But, the changing of the times is undeniable and in the last decade we’ve all been swept up to a certain extent. The point is that when we do get to ride two-strokes like Yamaha
’s 2011 YZ125, we get to reexamine an old concept with fresh eyes – and what a treat it is.
Yamaha is the only Japanese manufacturer still importing two-strokes to America, and after a day of riding them at Milestone MX
we’re sure glad it makes the effort. Yamaha ships these bikes all over the world and rather than making different models for different countries, the Tuning Fork brand has elected to standardize the bike for easier global distribution. For 2011 the YZ125 receives minor updates which make it able to pass European standards. Passing a 96 dB sound limit is the concern and the 125 gets a revised silencer in order to meet code. Core diameter increases from 27 to 30mm and the silencer is 75mm longer overall. The new dimensions allow it to be packed with nearly 72% more glass wool. The 38mm Mikuni carburetor gets some internal tweaks to make the bike run properly with the new exhaust by allowing more fuel. A needle change equals a half-clip richer and the main jet jumps to a 430 (from 410). Our day at Milestone revealed a strong and clean-running 124cc machine. The piston squishes premix into a 54 x 54.5mm bore and stroke which delivers power through the six-speed transmission.
The YZ gets a new exhaust silencer which helps
it stay at 96 decibels. All of our riders found that
the bike has plenty of power to get over jumps.
“The YZ has a great overall powerband for a 125,” says intermediate tester, Nick Thiel. “It pulls itself well through all the corners and has good throttle response as long as you stay on top of gear selection - which is normal for any small-bore two-stroke. I had no problem getting over any of the jumps and even found myself over-jumping a few due to how much extra corner speed I would carry. This being said, I would say it is still under-powered compared to any of the 250F motorcycles. But if you’re looking for a great motorcycle to have fun on or looking for a great transitional bike from the 85 to the 250F, this bike is awesome.”
Riding the 125 is an act of precision. It’s pretty easy to keep the right wrist tipped back, but the little YZ requires an active left hand and foot to keep it driving forward. The clutch and tranny work flawlessly and require very little pull. We hammered through the gears without the clutch and the blue machine never complained, just changed cogs and went on its zippy way. It doesn’t take long to get back in the swing of riding these tiddlers and by the second session lines were coming together and by the end of the day even our slower rider was clearing everything on the track. Even though the YZ takes a lot of effort to ride, it’s still easier to put in longer motos than any other big bike. Manhandling a 125 is nothing like a 250F, and even when it’s on the pipe the bike never yanks it ProTaper handlebars out of the rider’s grip. Being aggressive at the controls is a necessity and the reason it’s so much fun to ride.
“I rode the bike hard for 30 minutes and had very little clutch fade, which was great,” comments Thiel. “The transmission worked flawlessly and I had no complaints. After riding the bike for a while I noticed the gearing was a bit short but I think this helps with keeping the bike on the pipe thus helping to alleviate potential clutch fade.”
Keeping the motor singing is a thrill in its own right, but the thrills just get bigger when it’s time to pitch the 125 into a corner. With a claimed curb weight of only 208 pounds, the YZ is feather-light. The 48mm Kayaba fork and shock were both a little soft for our testers, but they still handled everything with ease. Big jump landings were the roughest, but the Kayabas were especially good on braking bumps. The lightweight machine flies into corners with control and a lack of engine braking helps it skim across corner entry. Once in the turn, the YZ is extremely predictable and is more than willing to find any rut your eyes can identify. Also, because its power isn’t explosive, tracking through flat turns is easy as well.
Handling on the YZ125 is a strong point. Our testers had the confidence to throw it around and take any line through the turns at Milestone MX.
“The handling was the best part about riding this bike,” Thiel says. “The line choices are endless. Anywhere you want to go whether it is inside, outside or down the middle of a flat corner, the bike works great. It has amazing stability through the rough sections and also felt light and flickable in all the corners and on the face of jumps.”
Yamaha’s aluminum chassis is easy to grip and takes little input to throw around. The rider triangle is confortable despite our larger testers who appreciate the lofty 39.3-inch seat height.
“I have always meshed really well with the ergonomics of Yamahas,” continues the 6’1” Thiel, “and the 125 is no exception. It has a nice midsection with a nice open layout. It may be a bit cramped for anyone taller than me, but I had no complaints.”
Even though Yamaha hasn’t dumped a lot of R&D into the YZ125, at least it’s still available in US dealerships. As an important stepping stone from youth machines to full-size dirt bikes, the YZ is a smart move for someone looking to ease into the world of high-powered motocrossers. It’s also a smart move for anyone wanting a ride that’s easy on their bank account. Maintaining a 125 is far less expensive than a 250F and the MSRP of $6250 is significantly lower as well. There wasn’t a single journalist or test rider who wouldn’t mind having the YZ in their garage permanently, regardless of skill level. Because of its impeccable handing, light weight and wide-open-all-the-time engine, this is a top choice for any rider whose top priority is having fun.
“After riding the YZ it made me remember how much fun screaming around the track on a 125 still is,” sums up Thiel. “Being close to $1000 cheaper than a 250F, this bike is the absolute most fun you can have for the money.”
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