actory Connection Honda knows what it takes to win. When Kevin Windham and Mike LaRocco take to the track they’re powered by Wiseco. Windham’s relied on his Wiseco CR450F High-Compression Piston all season long, and LaRocco’s never left the gate with anything but a Wiseco Single-Ring Race Piston filling the cylinder of his CR250. They’re not alone either. Plenty of pro race teams run Wiseco pistons—for one very important reason. With a Wiseco in the cylinder a motorcycle makes more horsepower, keeps making it longer between services, and that horsepower is always right there, instantly available at the twist of the throttle.
All this race-ware is readily available to everyone, too. Wiseco, the racer’s choice, is accessible to anyone wanting the very same technology and cutting-edge performance factory teams rely on. It’s all just a phone call away, in stock at Parts Unlimited.
     Start with that High-Compression Piston powering Kevin Windham’s No. 14 450F. Wiseco’s really done a job here, dramatically improving the performance and life-span of those new-generation OE “slipper skirt” pistons found in modern four-stroke engines. While those factory pistons provide good performance, it comes at a cost. They wear out and become virtually useless, performance-wise, pretty quickly. The factories recommend just 15 hours running time before a ring change, and recommend only 30 hours on the pistons themselves. This makes the Wiseco High-Compression Piston a savvy replacement, and it’s offered in a 12.5:1 compression ratio, a half-point higher than stock. There’s a 13:1 version available now, too. And remember, those Wiseco replacement pistons come with specially coated skirts to enhance break-in and provide a much-needed longer service life. Needless to say, Kevin Windham isn’t the only guy running a Wiseco in a 450.
     Mike LaRocco’s not alone with his Wiseco piston in a winning 250, either. That No. 5 Factory Connection Honda has plenty of company when it comes to using Wiseco. Serious pro-250 teams, and plenty of hard-charging amateurs and privateers, use the Wiseco single-ring piston, too. These guys find that with Wiseco their bikes make a lot more power, and to keep things that way Wiseco has taken this piston design even further. To prevent any type of galling, for instance, the ring groove and wrist pin area on the Single Ring are specially treated with Wiseco’s “E coat” process for extra protection in those critical areas. This 250 upgrade isn’t limited to just Honda, either. Wiseco’s “E-coated” Single Ring 250 Pistons are available for all current-model CRs, KXs, RMs and YZs, too.

     On the subject of pistons, don’t forget what Wiseco has for those super-popular 250 four-stokes and the ultra-hot 125s. Wiseco’s 13.5:1 High-Compression Piston for 2004 model RM-Zs and the KX250F is a real wake-up call for those bikes, and the GP Series 125cc Race Piston is the “racer’s choice” just about everywhere. Now, no one needs to tell you how popular 250 four-strokes are, they’re all over the racing scene. Wiseco’s got them covered, too. New 250 High-Compression Pistons bump the ratio up to 13.5:1, resulting in a noticeable boost in bottom-end grunt without sacrificing or compromising performance anywhere else. It’s a great swap. The GP line of replacement 125 pistons make sense, too. All by themselves they’re good for 1.5 more horsepower over stock, a huge jump for a 125. These pistons are all ring-pinned on the centerline of the exhaust to reduce any chance of the ring catching in the ports, and to enhance that all-important mid- and top-end there’s no boost porthole in the back of the piston. The ring groove and wrist-pin area are treated with that Wiseco “E coat” system, too, guarding against any type of galling. Those super-trick 125 GP Pistons are available for all current CR, KX, RM and YZ bikes.
     With Wiseco it isn’t just pistons, either. Those Parts Unlimited warehouses have plenty more from this 60-plus-year-old company to keep off-road bikes running strong and charging hard. There are Forged Clutch Baskets, Replacement Crankshafts and even complete Hot Rod Stroker Kits, and coming from Wiseco you know it’s all quality.
     It’s no secret that OE clutch baskets live a pretty short life. They’re cast pieces, and that’s just the way it is. Wiseco’s upped that durability factor with a fully machined forged-billet basket, going to the next level of performance and durability. The WPP Forged Clutch Basket eliminates all the problems and worries inherent with those stock cast pieces. And why bother rebuilding an OE crank when Wiseco has brand-new Hot Rod Crank Assemblies available? And the price is right. A YZ125 crank, for instance, retails for around $200, no core charge, no exchange. The performance and reliability of that replacement Wiseco Hot Rod Crank exceeds OE specs, too. And talking about exceeding OE specs, take a look at the Hot Rod Stroker Kit With 795-Series Piston that Wiseco has for the Yamaha Banshee. The kit includes a 5mm longer rod and a 4mm stroker crank, all matched with Wiseco’s 795 Series pistons and there’s even a complete gasket kit in the package. It’s a straight bolt-in, too. No case work is needed, just a bit of cylinder gains you 375- to 400cc’s displacement. This kit’s a real value package, too. It sells, complete, for under $900 retail.
Pistons to crankshafts to stroker kits to clutch baskets, Wiseco has what it takes to win. Guys like Kevin Windham and Mike LaRocco know it, and now you do, too. Everything’s in the Parts Unlimited warehouses right now, ready to ship.

Hot Rod Stroker Kit With 795-Series Piston

Wiseco also makes forged clutch baskets.