FUEL INJECTED HONDA TRX450R

It’s coming. But it’s not here yet. We’ve been hearing the rumors, watching the market and listening for clues, and it seems that Honda’s new sport 450 is right around the corner—but will probably be called a 2018 model. We hope it will be far more than a fuel-injected version of the current 450R. The new Honda will have an entirely new motor and chassis. It will be lighter and faster than the current version, and it will probably be even more reliable.

We first started hearing stories about the TRX450 EFI back in 2009. That was when Honda released its newest-generation two-wheeled 450cc motocrosser. At the same time, the word from our spies in Japan was that the company was well into its reliability testing phase of the quad version, which is the last step before production in Honda’s rather elaborate development process.

But market forces intervened. The existing 2009 TRX450R took a double-barrel shot point-blank on the showroom floor, and has been continuously upgrade over the years. First, the housing market collapsed and took most of the buying power away from the middle-American ATV customer. With reduced home equity and no lenders to provide financing, the sales of all sport quads took a big hit. Then, Yamaha beat Honda to the punch with its phenomenal YFZ450R, and that took what few buyers there were. The bottom line was that there was an oversupply of 2009 Hondas in the warehouse, and the corporate decision makers wanted to see those numbers decline before they introduced a new machine. This begs the question, why are we still waiting? Its 2015 and the new Honda we hope for still hasn’t come out.

The Honda warehouse is now empty, and dealers are finally asking for something new. But the bigwigs in charge still don’t think the economy has recovered enough to support the tooling cost of a new sport ATV. Thus, there will be a 16 TRX450R, but it will be nearly identical to the 2014 version. The 450 EFI will have to wait just a little longer.

ENTER THE 450i
When it does arrive, the new ATV will have a motor that’s very similar to that of the two-wheeled CRF450R. It will have the latest generation of the Unicam design, which is claimed to have the advantages of a double-overhead-cam motor without the weight of two separate cams. It does this by placing the cam directly over the intake valves, which are larger and heavier than the exhaust valves, and using a rocker arm to operate the two exhaust valves. This design allows higher revs because of the reduced drivetrain weight of having no intake rocker arm. That design was used on the older TRX450R motor, too, but everything on the new motor will be designed to keep weight to a minimum. The rod and the cylinder will be shorter, and the rev ceiling will be around 11,500.

There’s one big advantage in the delay. The two-wheeled version of the 450 EFI has been out for seven years, and Honda engineers have a wealth of feedback from that market. For example, the four-spring clutch from turned out to be a weak spot on the CRF motor, so that will be beefed up. On the other hand, the gearbox of the existing TRX450R ATV is that machine’s weakest point; it has been that way since 2006 when the motor was last changed. At that time, Honda introduced the electric-start 450X off-road motorcycle, and someone had the bright idea to put the same motor in the ATV. It would have been fine, except the gearbox wasn’t as strong as that of the original TRX450R. As a result, racers like Joe Byrd continued to base their race quads on the 2005 TRX450R. In the hands of the general public, the 2006 gearbox was adequate, but Honda is never satisfied with just being adequate. So, the new gearbox will be stronger.

But the big news, of course, will be the fuel-injection system. Honda engineers have two choices here: they can use a Keihin system, just like the motorcycle, or go to Mikuni. Japanese manufacturers also like to keep two suppliers on hand for most components, and the Yamaha YFZ450 uses a Mikuni system with good results.

A FULL RACER?
To the disappointment of those who expect a race-ready 450, that isn’t in the cards. The Honda will have to meet EPA standards, which means it will be clean and quiet. The motorcycle version avoids these standards by being imported as a closed-course competition vehicle. That designation won’t work for a quad, as research shows that very few of them are ever raced. Yamaha and Kawasaki both have EFI systems that meet governmental emission standards, and both perform well in stock trim. It is unfortunate that Kawasaki just stopped production on their sport 450. The only glitch is that if you replace the muffler and open up the airbox for more performance, the injection will be too lean, and some EFI modifications will be necessary. Suzuki tried to get around this by “hiding” a second fuel-injection map within the Quadracer 450R’s electronic brain. By installing the Yoshimura Cherry Bomb, you could access those settings and get the full benefit of an aftermarket pipe. We liked that system, but the government didn’t, so the Suzuki was removed from the market a while ago.

Suzuki got in trouble for having a system that was too easy to alter,  and the 450LT-R was taken off the market while things were sorted out and didn’t come back. Honda’s fuel injection will probably work very much like that of the Yamaha and Kawasaki. If you want more performance than stock, you will need to modify the metering with an aftermarket part, and corporate Honda will keep its distance. The good news is that the aftermarket will react quickly.

As far as the chassis goes, Honda has long been a big proponent of aluminum as a material. The fact that Yamaha, Can-Am and Kawasaki all beat Honda to that feature has probably been a source of internal annoyance. We expect a full aluminum frame, most similar to that offered on the Kawasaki KFX450. Chassis width will remain approximately the same as the current TRX450R. Later, the market might support a wide-track edition, but not right now.

OK. THEN, WHEN?
Honda dealers won’t complain about the unchanged 2015 model because the price will still be less than that of the Yamaha and Kawasaki, and that‘s a critical factor in the current market. But Honda, still, is a company with a lot of corporate pride, so we‘re sure that the new 450 EFI won‘t be far behind. They just can‘t help themselves.