WHAT IS IT? An ultra-trick exhaust system designed to boost performance on the 2009 Kawasaki KX250F. This is the exact exhaust pipe that Ryan Villopoto used on his 2008 AMA Championship KX250F.
WHAT’S IT COST? $999.95.
WHAT’S IT DO? There is only one aftermarket part on a motocross bike that can vastly improve performance, increase power spread, change the tonal quality, and reduce weight significantly, all at the same time. What is it? An exhaust system. Pro Circuit understands this better than anyone else. They built their exhaust pipe reputation with riders like Rick Johnson, Bob Hannah, Jeff Jennings, Ricky Carmichael, Jeremy McGrath, James Stewart, Ryan Villopoto and Chad Reed. They have been at it since 1978. If there is a twist, trick or secret to exhaust pipes, Pro Circuit knows it. How do we know? A quick look at Pro Circuit’s new TI-4R exhaust system screams of works trickery. The system is composed entirely of titanium (save for the mounting bracket, springs, rivets and screws). The Ti end cap is welded instead of being stamped, which is exactly what team riders Austin Stroupe, Christophe Pourcel, Jake Weimer and Ryan Morais use. Finally, the Ti-4R comes with a repacking kit and hardware. Simply put, the Ti-4R exhaust system is the exact same unit that the top pro riders use.
WHAT STANDS OUT? Here’s a list of things that stand out with the Pro Circuit Ti-4R KX250F exhaust system.
(1) Installation. Installing the Ti-4R exhaust was a breeze thanks to tight tolerances and swiveling one-way head pipe springs (before, both ends of the springs would constantly move). Here are the basic steps: (a) Install the head pipe (keep the mounting nuts loose). (b) Slip on the one-piece midpipe/muffler. (c) Be sure to apply the included anti-seize grease at midpipe junctures. Otherwise, the system becomes difficult to separate after it heats up.
(2) Performance. In stock trim, the 2009 Kawasaki KX250F engine profile has a wide spread of power, but apart from its perfect placement, it is not exceptionally powerful. The addition of the Pro Circuit exhaust didn’t hinder the crisp bottom end, but it did make large gains in the midrange and top end (areas where the KX250F needs improvement). It is much better than the stock exhaust—especially for Intermediate and up riders.
(3) Weight. This baby is light! Pro Circuit used copious amounts of titanium to decrease overall weight. How much did the Pro Circuit unit save over the stock system? 1.3 pounds, to be exact.
(4) Sound. Kudos to Pro Circuit. They vowed that every one of their 2009 exhaust systems would meet or beat the AMA/FIM sound limits. True to their word, the KX250F Ti-4R exhaust is 1.6 decibels lower than the stock KX250F exhaust.
(5) Quality. MXA test riders don’t like mufflers that are riveted together. It makes repacking an annoying, time-consuming chore, and Pro Circuit always used rivets. No more! Pro Circuit replaced the rivets at the base of the muffler with Allen screws. Pro Circuit also developed a stronger aluminum mounting bracket to hold the muffler body to the frame (they had previously used a welded bracket that was prone to cracking). The final touch for 2009 is a welded titanium end cap. It replaces the stamped end cap, not for quality reasons, but because consumers wanted the same end cap that Ryan Villopoto used. Pro Circuit obliged. Nice work.
(6) Place of manufacture. The Pro Circuit Ti-4R exhaust system is made in Corona, California.
WHAT’S THE SQUAWK? Price. Two years ago, the Pro Circuit Ti-4 Lowboy exhaust was under $800. Today, it costs almost $200 more.
The Pro Circuit Ti-4R exhaust system is a true-to-life works part that is available over the counter. That’s worth a lot in today’s marketplace, but, unfortunately, all those works-style perks add to the cost.
Kawasaki Motorcycle test