Quickfix

QuickFix

With my motocross background, I appreciate off-road bikes that have MX-like characteristics. The Suzuki RMX450ZI tested last month impressed me in that way, but as an all around off-roader, it fell short in one important area; fuel-tank capacity.

The bike’s fuel range is laughable, as the tank’s 1.6 gallons might get you just 40 miles.

I solved that problem by installing a 2.6-gallon tank from IMS ($275; www.imsproducts.com) for the RMX450Z and RM-Z450 MXer. Available in either white or black polyethylene, the tank slides in place nicely and allows retention of the stock radiator shrouds. The tank is slightly wider and higher, but it doesn’t affect my ability to get forward on the seat.

Trail riding stinks without a good set of handguards, so I also bolted on a set of Fastway Flak shields ($45; www.promotobillet. com). Fitment is simple using the billet aluminum mounting system. The guards do not interfere with the standard handlebarmounted controls and offer ample protection for sensitive paws.

While I was at it, I decided to power-up with a Cherry Bomb from Yoshimura ($40; www.yoshimura-rd.com). This little plug-in is a Coaxial Relay Bypass Module (CRBM) that

connects to the RMX's wiring harness and optimizes the

engine-management parameters. It's claimed to let the RMX gain up to seven hp but is intended only for closed-course racing. A Cherry Bomb is included with all of

Yoshimura’s RMX450Z exhaust systems, so I decided to give an RS-4 Stainless Full Exhaust ($595) a try. I wanted to shave a little weight off the Suzook, but its stock exhaust already is so light that the Yosh muffler’s aluminum sleeve and carbon-fiber endcap only dropped ounces, not pounds. Yoshimura also sells a titanium system that is much lighter, though it retails for $995. The RS-4’s muffler incorporates Yosh’s Duplex Chamber, an internal resonating section designed to decrease sound levels while increasing midrange torque.

With the Yosh system, the RMX is able to breathe better, trading some of the motor’s zippy high-rpm performance for stronger lowend and midrange grunt. But the resonating chamber not only didn’t kill exhaust decibels any more than stock, the exhaust was actually louder. Loud pipes are problematic in sensitive riding areas where land battles are being fought, so I can only recommend this system if you intend to race the X where sound levels aren’t a big issue.

As far as I’m concerned, I could live with or without the increase in low-end allowed by the aftermarket exhaust system; as I said before, I like the MX-like top-end hit of the stock RMX. But the 60-percent increase in fuel range allowed by the IMS tank and the added protection of the Fastway handguards now allow me to enjoy the full off-road potential of the RMX450Z.

Ryan Dudek