MC Tested: Motion Pro Rev2 Motorcycle Throttle Kit

Smooth throttle input is always important, but on a low-power bike like our long-term KTM RC390 racebike you want to get to 100 percent throttle as quickly as possible. With the stock throttle tube that means twisting your wrist and then dropping your elbow. That's not ideal, especially when you're leaning off the bike!

To get a shorter twist we investigated a few options including an RC8 tube and a G2 Ergo replacement throttle, but eventually decided give Motion Pro's Rev2 throttle kit a try. The setup is available for street bikes and motocross machines and includes a throttle tube, housing, five interchangeable throttle reels, grips, and model-specific cables for $165.

Those throttle reels are the key to the kit’s appeal. They come in four different diameters (35, 40, 45, and 50mm) plus a progressive profile. Swapping reels lets you slow down or speed up the throttle pull to suite your preference or conditions, with each 5mm increase in diameter reducing throttle twist by about 10 degrees. Swapping reels is easy (just slide the cable cover down, unbolt the housing, unhook the throttle cables, and make the change) and can be done in about 5 minutes. For racers competing at different tracks and dealing with various weather conditions and traction levels, the Rev2’s reels are as useful as switchable engine modes meant to address the same challenges.

Since each kit is model-specific installation should be fairly straightforward, but hey, this is the RC390! Things always seem to be a little trickier with the KTM (I'm referring to the Tyga rearsets I installed and the Mivv exhaust we put on), and this throttle is no exception. As with any bike you have to remove the old cables (or single cable, as is the case with the RC's stock pull-only arrangement) from the throttle body or carburetor and hook up the MP lines, but on the RC390 the stock throttle housing also incorporates the kill switch and starter button. That meant breaking out the wire strippers and soldering iron to wire up an aftermarket switch cluster. (Also available through Motion Pro for $73.) The RC always keeps things interesting!

The KTM’s stock throttle reel is about 35mm, so I immediately bumped up to a 40mm reel and then later settled on the 45mm reel for what is approximately a 1/5-turn throw. Talk about a quick-turn setup! Getting to WOT is easy now—no wrist contortions or re-grip necessary.

See the throttle in action (and note how much time it spends at wide open) in this onboard video from a race at Sonoma Raceway, below.

The Rev2 is built with typical Motion Pro quality and attention to detail. The super-slim throttle housing is made of powder-coated cast aluminum, the cable holders have locating pins for quick and easy assembly, and there are machined-aluminum adjusters on the cables. It's a professional setup, and that's exactly who the kit was designed for. An $80 G2 Ergo throttle tube or a throttle swap from another model is a more affordable solution for anyone that wants a subtle change, but for those that want a bigger change or see a need for regular and easy throttle-throw adjustment, only the Rev2 will do.

MOTION PRO REV2 THROTTLE KIT
PRICE: $165
CONTACT: motionpro.com

MC GRADE: A
VERDICT: An elegant solution to a very specific issue—yet another thoroughly thought out and expertly executed product from Motion Pro.