Factory Off-Road Bikes—San Diego Powerhouse’s Honda CRF450L

Prepping Honda’s dual sport for Vegas to Reno—while remaining street-legal.

San Diego Powerhouse’s Honda CRF450L
It takes a careful eye to confirm that this isn’t a CRF450X racebike, but a San Diego Powerhouse-built CRF450L dual sporter that remains close to street-legal. You’d just need to put the license plate and a mirror back on.Mark Kariya

One of the most anticipated motorcycles of 2019 was Honda’s CRF450L dual sporter. Honda claimed it was the closest thing yet to a genuine dirt bike—sharing many parts with the dirt-only CRF450R, CRF450RX, and CRF450X models—while remaining 50-state legal.

But early internet chatter produced mixed reviews, with many critics pointing to its claimed 289-pound all-up weight ready to go with a full tank of fuel and alleging anemic output from the four-valve Unicam engine supposedly derived from the 450R motocrosser.

San Diego Powerhouse’s Honda CRF450L Renthal Twinwall handlebar in BRP mounts, Acerbis hand guards, A’ME grips, and Scotts steering stabilizer.
Baja Designs provides plenty of light output, the two units fitting nicely inside the stock shell while powered by the standard stator. A Renthal Twinwall handlebar in BRP mounts, Acerbis hand guards, A’ME grips, and Scotts steering stabilizer help the rider control things comfortably. Note too the tiny LED turn signals located next to the top triple clamp bolts. While they may not follow the letter of the law in regards to size and spacing, they are functioning items with a matching pair integrated into the rear fender and are much less prone to damage than the stock items.Mark Kariya

In actual use, however, the consensus was that the 450L wasn’t really that bad. In fact, it was surprisingly competent on the trail, despite being on the somewhat portly side compared to its European competitors.

To put the issue to rest and prove the new bike merited more respect, San Diego Powerhouse’s Bobby Youngs decided to build one into a racebike equally competent to the race-winning CRF450X (yes, the new X has won in Baja already, going two for two so far in SCORE’s World Desert Championship this year). And with budget not allowing a full-fledged effort for his usual Slam Life Racing (SLR) Honda riders, he offered it to privateer Jacqueline Carrizosa, who planned to tackle the distance for the second time as an Ironman Expert.

“I always thought it would be cool to have a bike that you could cruise down the street and go to the grocery store on, but if you wanted to, you could take the license plate off and go race it,” Youngs begins.

“To start, it’s simplifying the bike,” meaning removing some of the extraneous items that serve primarily to meet emissions and other regulations. “There’s a lot of stuff on there that’s kind of unnecessary [for dirt applications] and extra clutter that you can get rid of to lighten it up and simplify it and just make all the systems on the bike more efficient.”

One of the first things he chucks is the stock muffler with its integral catalytic converter, replacing it with a full Pro Circuit T-6 spark arrestor-capable exhaust, which is 7 pounds lighter. That, of course, also helps liven power delivery and is, coincidentally, the system used on the CRF450Xs Youngs builds for SLR Honda’s Baja efforts.

He also installs the San Diego Powerhouse thermostat-delete kit, as he deems the standard system unnecessary for most race applications.

“We get rid of [the thermostat], which is a pretty big piece, but it’s all the stuff connected to that [which is heavy and fairly complex]. It has [an emissions] system that injects unburned [air-fuel mix] out of the intake into the exhaust to lean out the exhaust [and meet emissions requirements] so it reads that it’s running leaner than it is.

“There’s a purge system that bleeds the air out of the gas tank and there’s an oil catch can that comes off and catches [vapor from] the crankcase vent pressure and excess oil, so we remove a lot of those systems to lighten up the bike along with the tail part of the bike—it has a big tailsection with a big rear-brake light, license plate mount, and turn signals.

“We actually take an X rear fender and modify the subframe so that fits, and put all the lights inside that fender so it’s a lot more streamlined.”

For the racebike, he left the license plate off, but it does still carry the micro LED turn signals at both ends, which may not follow the letter of the law in regard to size/spacing, but they still work! The low-profile X LED taillight includes a brake light, which Youngs set up so that only the front brake activates it—another nod to diet via eliminating systems. After all, on the street, the front brake is the one used most.

In front, a Baja Designs Squadron with its four LED bulbs provides copious output. Two additional bulbs above the Squadron act as floods and retain the standard high/low function switch to remain street-legal. In addition, they sit comfortably within the standard CRF450L headlight shell. (Yes, the standard horn still works too.) The standard 120-watt stator provides more than adequate power for this setup.

San Diego Powerhouse’s Honda CRF450L with the thermostat-delete kit plainly visible.
AHM massaged the suspension, firming it up with slightly stiffer springs while adjusting valving for predictability and more control at both ends. This is easy since the internals are identical to the race-spec CRF450R and RX. Here, the thermostat-delete kit is also plainly visible; it reduces a number of parts that aren’t necessary on a racebike, thus cutting weight and simplifying the layout.Mark Kariya

“From there, we do work to the suspension [with AHM Factory Services], obviously. It’s a little soft stock to where you’d need it to race it aggressively.

“The good part about the L is the suspension that’s on it—besides on the fork there’s a little mount for the speedo—but the fork and shock are the same components that are on the motocross bike. So with the dual sport bike you’re not getting a dumbed-down version of the suspension; you have the same components and you can literally turn the suspension into suspension you could go ride motocross with.

“It’s set up for her, so it’s not going to be as stiff as what [AHM] is doing for other race teams, but that’s just specifically for her. It is valved stiffer than stock, definitely. The big thing they’re trying to do is make [the bike] controllable and predictable.”

San Diego Powerhouse’s Honda CRF450L racebike with a Vortex ECU.
A racebike needs power, and extracting more from the mild L starts with a Vortex ECU. That allows the mapping to provide the extra fuel needed for the Pro Circuit exhaust and RX-style cam kit. The OEM air filter is retained. (We and others wish Honda kept the tool-less airbox access for the X and L.)Mark Kariya

The final major part of the package is increasing output via porting, a cam kit Youngs developed that mimics a CRF450RX profile, higher compression, and modified mapping via a Vortex ECU. (In previous generations of the 450X, a popular mod was dropping the 450R cam in, but that’s not really needed in the new X; a side benefit is that the entire R head isn’t necessary either. The titanium valves are common across all the 2019 CRF450 models and Youngs keeps those in place, though RX valve springs replace the stockers.)

Actually, Youngs feels the Vortex is the first step for anyone seeking to increase power since the EPA requires the stock ECU to work only with all emissions components in place and, thus, feeds only the minimum air-fuel mix.

“You have to get the bike more fuel as soon as you start modifying anything, so the Vortex is very tunable and adjustable and they have a lot of really good stock maps when you buy it, then from there, there’s a lot of very tunable maps. As soon as you start modifying the bike, you can allow it to run correctly,” he says.

It took some time testing on the dyno as well as in the dirt before he came up with a map he was satisfied with.

“The power down low on the L, stock, is decent,” Youngs admits, “but from about 5,000 rpm and up, this cam adds torque and adds power all the way up and actually moves peak power up 1,500 rpm [giving] the bike over-rev. On the stock L, the bike kind of shuts down around 9,500 rpm and if you ride a motocross bike, that’s where the meat of the power normally is.

“This [cam kit] moves that up quite a bit,” he continued before adding, “I don’t want to say horsepower numbers because they’re always so controversial, but I can tell you that we dyno’d a bike that was all stock except it had the [Vortex] ECU and a Pro Circuit pipe on it and we dyno’d this bike back to back with the cam and the milled and ported head, and we gained just over 30 percent horsepower and 25 percent torque. We also moved it up [in the rpm]; not only is the curve [taller], it keeps going for another almost 1,500 rpm.”

To handle the increased power, Youngs replaces the stock clutch springs with the stiffer units out of the CRF450RX; the plates, however, remain standard. Getting that power to the ground is 13/50 gearing (stock is 13/51) with a Supersprox rear and RK EXW O-ring-type chain. (He set up the previous-generation five-speed CRF450X Baja racers with 15/48 gearing.)

San Diego Powerhouse’s Honda CRF450L with a six-speed gearbox.
Since the CRF450L (and X) has a six-speed gearbox, it’s unnecessary to gear really high for desert—and the stock engine wouldn’t pull it anyway. A 13/50 setup is all that’s needed to exceed 100 mph; the stock 13/51 yields over 90.Mark Kariya

“With having a six-speed gearbox, the stock gearing’s pretty good and you’ve got to get a lot more power to the rear wheel before you need to gear it [up],” Youngs insists. “It used to be for desert you’d go up one or even two teeth on the front. This bike with a six-speed transmission, you don’t need it. It’s not crazy to go over 90 miles per hour with the stock gearing. You’ve got to get the power before you start gearing it up.

“Now, we have the bike pulling much higher rpm [as well]. Like I said, the peak power is not at [9,500 rpm] anymore—it’s up over 10,500—so that and the tall gears translates into going faster because it can pull the higher rpm. We have a pre-runner with the same setup that does 107. I don’t want to say for sure because I don’t know 100 percent on this particular bike, but with this same gearing, same cam—actually [the pre-runner] didn’t have a port job or milled head like this one has. I’ve got to get Justin [Morgan] on it because he’s the only one who’s going that fast [regularly] to let me know!”

STI furnishes its new Tech 2 Pro D tires (designed specifically for desert racing) front and rear, the front being the slightly larger 90/100-21, which he feels is better in the desert arena. (Coincidentally, they’re DOT-approved for street use, making them a good choice for hard-core dual-sporters.) The latest Nitro Mousse foam inserts practically eliminate the possibility of flat tires. “We’re really happy with them,” Youngs declares.

San Diego Powerhouse’s Honda CRF450L
A 3.0-gallon IMS tank, MotoSeat seat, STI tires (filled with Nitro Mousse inserts), and Split Designs graphics help hide the fact that this is a CRF450L, down to retaining the kickstand, horn, and instruments. To bring it more in line with regulations, you’d need to reinstall the license plate and its new, lighter mounting bracket as well as a mirror—all quick and easy.Mark Kariya

Other notable items include the beefy IMS Core Enduro footpegs; Bullet Proof Designs sharkfin for the rear rotor; brake snake from San Diego Powerhouse as well as padding added to the inside of the pedal; A’ME half-waffle grips on the Renthal 997-bend Twinwall handlebar in BRP mounts; Scotts Performance steering stabilizer; Acerbis hand guards; slightly softer and wider MotoSeat saddle; 3.0-gallon IMS tank with quick-fill receiver (only for the race—not included in the photos); and mesh added for more radiator protection. Youngs replaces the standard 1.1-bar radiator cap with a 1.8-bar unit, thus raising the Maxima coolant’s boiling point. He keeps the OEM skid plate in place, however, deeming it more than adequate. Maxima Lubricants provides all essential fluids while Split Designs graphics tie it all together visually.

Compared to her personal YZ450F, Carrizosa noticed a huge difference, primarily in handling. “I was concerned with the height and weight a little bit because I’m a little person,” she admits. “I didn’t doubt that I could make it happen, but I knew that the weight and height would cause extra fatigue so that was one of my concerns, but it wasn’t an overwhelmingly big concern.”

After a couple of pre-race test sessions and more than 400 race miles though, the Honda grew on her: “I definitely noticed over the race course—and having raced the course previously—parts of the track that were immensely night-and-day different being easier for me to handle on the Honda 450L than on my [2015] Yamaha.”

The AHM suspension and six-speed transmission stand out as highlights on the San Diego Powerhouse machine.

“I remember specifically fighting [headshake with my Yamaha] where there were high-speed sections…and I’d have to slow down.

“On the Honda, even though I topped out at 85 miles an hour, overall throughout the whole course it was a lot faster and smoother in most sections.”

How much faster? By pit 12 late in the race at mile 430, she was ahead of last year’s time by seven hours!

Unfortunately, her race came to a premature end at mile 436 when she crashed, suffering a broken arm that may require surgery, but for her, it’s simply a bump in the road.

“I had a really good day up until that,” she insists, adding, “I shaved seven hours off this one, so I’d like to finish it in the daylight [next time]. Honestly, when I crashed, yeah I was a little tired, but I wasn’t exhausted. I think the bike really made a huge difference this year.”

For more information, visit sandiegopowerhouse.com.