We live in a world of cowards. The vast majority of entities in the ATV world have had all boldness, innovation and aggression stripped by a mood of corporate retreat. Factories will only make what they have made before—at least until that formula is worn out. That’s why we are left with the shrinking field of sport quads that we see today.

It doesn’t have to be that way. Case in point: the Eichner Honda 150. This is a sport quad with a state-of-the-art, liquid-cooled, four-valve, four-stroke motor. It weighs about as much as a 90cc kids’ quad, but it will outrun anything short of a full-size production 400. The most amazing part is that it isn’t the result of an extensive R&D project or a skunk-works hotbed of future technology. The entire machine was constructed of production parts that already exist on factory shelves. The only truly exotic aspect of the machine is the vision it took to put it all together.


When it was all done, the Honda Raptor 150 was like nothing in the ATV world.

Most ATV enthusiasts know all about Doug Eichner. He’s a long-time West Coast racer, a WORCS champion and a UTV pioneer with a long list of accomplishments. Today, he remains a racer and an enthusiast, but his job as a single father is his biggest focus. Doug, like many other fathers, was frustrated by the lack of a high-performance sport quad that was appropriately sized for a tween-ager. His son, Devin, is a bright kid who loves to ride, just like his dad. He started on a Polaris 90 and then progressed to a Yamaha Raptor 250. Devin loved the Yamaha, but unfortunately, that’s where the road for a youth-oriented ATV ends, at least as far as the major manufacturers are concerned. The Yamaha has an excellent chassis, but is powered by an air-cooled, two-valve motor straight out of the ‘70s. Yamaha rates the Raptor Y16, for riders who are at least 16 years old. That’s a conservative designation, which is understandable given the climate of safety concerns in the ATV world, but it leaves athletic, capable kids like Devin out in the cold.

After the Yamaha, the next logical step would be a quad that doesn’t exist in the known universe. A 400 or 450 is out of the question for a rider so young; it should be a quad with less weight than a 250 and a little more power. Doug stumbled on the solution almost by accident. He found someone who was parting out a Honda CRF150R. This is a motorcycle with a very interesting pedigree. Back in the mid-2000s, Honda decided that as a company, it no longer would produce two-strokes. For the most part, that required no sacrifice at all; the CR125R and CR250R two-strokes were already in the process of being replaced by the four-stroke CRF250R and CRF450R. But the CR85 was a problem. If it went away, it would leave a big hole in the Honda line. So Honda started working on a four-stroke replacement. It was actually a very difficult problem, because it would be very easy to end up with a bike that was both too heavy and too expensive for that market.

ATV racing legend Doug Eichner found a Honda CRF150R motor and put it in his son’s Raptor 250. It was a surprisingly easy project.

Eventually, the single-overhead-cam CRF150R motor was developed, and it was quite an engineering success. It was barely any heavier than the two-stroke and made excellent horsepower through a very high rev ceiling. Honda cut the necessary corners on the chassis in order to meet the target price. In terms of sales, however, the CRF150R was disappointing. Kawasaki, Suzuki and Yamaha watched closely to see if there was any demand for a four-stroke competition mini. All of them decided not to make one, leaving Honda all alone in the new segment.

The Honda motor doesn’t have as much torque as the original Yamaha 250 motor, but it revs forever and is almost 40 pound lighter.

That was 2007, so today there are used Honda 150s to be had, just like the one that Doug found. He paid $500 for the engine and radiators. Then he went to work. The motor that came out of his son’s Yamaha was much larger than the Honda motor, so it wasn’t that difficult. The swingarm pivot passes through the engine case on the Honda motor, so that was the determining factor on engine location. The motor mounts themselves were easy to fabricate. On a project like this, the airbox is usually the most difficult engineering job. But, Doug was able to use the Yamaha airboot with the Honda Keihin carb after he constructed a new airbox from sheet metal. On the output side of the motor, the sprockets lined up after a slight amount of offset work on the rear sprocket. The most amazing stroke of luck was that he could use the stock Honda exhaust system. It fit right into place with very little modification.

The A-arms are custom-made and 3 inches wider than stock. The original shocks actually worked out quite well.

On the chassis, he used the stock suspension, but he modified the A-arms to make the quad 3 inches wider. In the rear, he used an Alba axle that also was 3 inches wider than stock. He also used Alba nerf bars. Brand-new DWT tires and wheels were installed. The list of stock stuff is much longer: stock steering stem, stock spindles, stock swingarm, stock bodywork. This is no elite project where price was no object. Doug is a working man who has a budget. In the end, he estimated he had no more than 15 hours of labor invested in the quad.


What class would a 150cc quad fit into? None, yet.

When it was all done, Doug and Devin took the Yamahonda straight to the sand dunes for a shakedown. There were no issues, so two days later, we got our chance to try the hybrid for ourselves. First, you have to know that we already love riding the stock Yamaha Raptor 250. It’s sized just perfectly so that kids and adults both love it. The fact that the stock motor is a little slow never bothered us. Just as long as you have another rider on another Raptor 250 to play with, you can’t help but have fun, simply because there’s nothing better in the category. Doug’s machine messes up everything. Now that we’ve ridden it, we’ll probably never be as satisfied with a stock Raptor. The 150 feels phenomenally light. In fact, the finished weight of the project is close to 40 pounds less than stock. That translates into a machine that makes you feel like Super Quad Rider. You can do anything! Kicking the rear end out in a turn doesn’t require huge body English and big muscles; it’s just a small weight shift and a burst of throttle. Even Devin, who weighs about 75 pounds soaking wet, is able to manhandle the 150 like a pro.

Alba nerf bars were used, but had to be modified to allow clearance for the Honda’s kick-starter.

Everything about the project seemed to work out naturally. The suspension, for instance, should have been too stiff, considering the reduced weight of the motor and Devin’s size. But in front, the increased A-arm length countered that nicely, putting more leverage on the stock shocks, which have very limited adjustment. In the rear, the stock KYB shock has just enough adjustability, although Doug admits that the next step in the process will be Fox Float shocks all the way around.

In terms of power, the 150 motor is easily as strong as the original Yamaha 250. It even has a surprisingly wide powerband; it’s just that all the power happens at a much higher rpm level. The 150 is a modern screamer and is a little more demanding than an old-world 250 mentally, if not physically. That’s probably part of the machine’s appeal. It makes you want to ride fast and hard, and is very rewarding when you put some effort into your ride. By the same token, all of the utilitarian traits of the Raptor are gone. You wouldn’t use it on the farm, and it would be a crime to install racks or hitches. The 150 doesn’t have to torque to be a tractor. Thank goodness.


DWT tires and wheels finished off the project nicely.

Being racers at heart, we asked the same question as everyone else: What class would you race this in? No one knows. The truth is, racing was never the goal behind this project. Doug Eichner is an enthusiast as well as a racer, and Devin is cut from the same cloth. The Yamahonda is made for fun, nothing more or less. For the next few years, it will serve to fill a gap that exists in the current ATV world. After that, if the younger Eichner wants to go ATV racing, then there are lots of machines to choose from. But, if he wants to keep riding the 150 forever, that will work too.

Comments are closed.