Meet two-stroke horsepower guru Nick Rhine and his mechanically fuel-injected YZ250 2-stroke engine powered by a custom Wiseco piston.
Not all superheroes wear capes, and not all rocket scientists work for NASA. Maybe engineering whiz Nick Rhine isn’t exactly a rocket scientist by trade, but the 63-year-old certainly knows the inner workings of a motorcycle engine. Rhine fell in love with motocross from a young age. He happened to live near Washougal, Washington, before it became a celebrated stop on the AMA National circuit. Then came motocross. With a passion for riding and a European style track in his backyard, Rhine was destined to become a racing superstar. He competed against Chuck Sun and Rick Burgett – two studs from the Pacific Northwest – and managed to beat them.
“As the sport of motocross grew, a lot of people would show up to race at Washougal,” explains Rhine. “Inside of three years I basically went from not racing to turning Pro. I started getting into buying Honda Elsinore’s that were $150, and I would build them up. A guy I knew had gotten out of the Navy, and his dad had an automotive machine shop. He loved motorcycles. Well, he walked up to me at one of the local races and wanted to get involved. We started developing the Elsinore. It quickly became more fun for me to build the engines than to race them. I didn’t know it would get to the level it’s at now!”
Fast-forward a few years. Nick married the love of his life and turned his attention to family. Some 17 years later, Rhine was sucked back into the sport out of necessity. As Nick puts it, “Phone calls started to come, because my kids knew that I could fix things. I worked on Honda CR80s and launched a little company to get back involved.”
That company is called Factory Fire1, which grew into a race program (Team Fire1). Rhine helped a slew of mini riders over the years, including Levi Kitchen. While Kitchen was racing in the Super Mini class, Rhine got the crazy idea to develop a fuel-injected two-stroke. Rhine was successful in his quest.
“The bike was really too fast to ride. We got it dialed in and ran with all of the top guys. I was never really all that excited about letting it go to the Amateur Nationals, because of the claiming rule [Ed. Note: an antiquated rule where a rider has the ability to purchase a competitor’s motorcycle at a National for two times the manufacturer’s suggested retail price]. That sets up an opportunity for people to buy or steal information.”
Next came the fuel-injected 2006 Honda CR125. Austin Ulrich piloted the bike to the 125 Dream Race win in 2013. The transformation wasn’t a walk in the park. For example, Rhine had to machine an idle adjustment knob designed for an FCR four-stroke carburetor and fit it to operate the power valve. He figured out that one full turn on the knob equaled two degrees duration on the exhaust. Yes, Nick Rhine is that smart.
“I have a three-dimensional mind,” explains Rhine. “That’s probably why I don’t sleep much. I basically engineer things like a movie in my mind. For years, I could see inside motors. You would think that everyone had already figured everything out in engine design, but I knew there had to be something else going on that I could improve on. The two-stroke layout blows my mind when I think about how the piston runs up and down 166 times a second at 10,000 rpm. It doesn’t even seem possible. At the same time, at bottom dead center the exhaust port is open and the transfer ports are open. The whole entire pipe is open to the wind. How in the heck does fuel not run out? A lot of that is in port timing and angles. That wasn’t so much a mystery to me. Instead, it was trying to find the next something.”
That next something came in the form of a Yamaha YZ250 two-stroke. A local rider by the name of Mike Smith was interested in racing the 2019 Wiseco Two-Stroke World Championship at Glen Helen in Southern California. Rhine knew that it was going to be a massive undertaking, but he did it anyway. Not only did Nick like the idea of working with Mike Smith, but he also enjoyed the process of figuring out the puzzle of creating a mechanically fuel-injected YZ250. Rhine didn’t have a blueprint to work from. Fortunately, he had background on the technology from his time as an engine builder and in making other fuel-injected bikes. In fact, the YZ250 was the seventh fuel-injected bike that Nick made. He was well aware of the difficulties in figuring out the fueling, ignition, and other vital areas that needed transforming, massaging, and tweaking.
Rhine set to work engineering and fitting pieces by hand. He used injectors that had to be made and welded on to the cylinder. The special injector plate was a chore. Tuning the YZ250 took quite some time, and it had to be done over the phone because Mike Smith’s schedule didn’t like up with Rhine’s. Keep in mind that this bike was mechanically fuel injected, meaning that Nick didn’t use electronics to make fuel delivery work. Jets in the injectors changed fuel output. As one would expect, one slight miscalculation in fuel flow could have detrimental effects on the rider. Oddly enough, none of these things were the most challenging part of getting the bike built.
Check out Mike Smith's Nick Rhine's complete trip at the Wiseco 2-Stroke Championships. Nick discusses the engine build at 4:32.
Had it not been for Wiseco, the biggest hurdle would have come in finding the correct piston for the job.
“There are some characteristics of the fuel-injection design I found out when building the Honda CR125 that applied to the YZ250,” Rhine explains. “One of the characteristics is how the fuel flows through the ports when it’s injected. I struggled to find a piston on the market that would work for my application. Wiseco was instrumental in what I considered to be the hardest part of the equation. I called different piston companies, but they didn’t treat me well. They weren’t responsive, and others tried to force me into buying huge quantities of that specific piston I wanted. With Al at Wiseco, it was like chatting with a buddy. He wanted to help. I asked him for a timeframe, and he made it happen. Keep in mind that I wanted to display a bike to the world that no one had ever seen. This was a big deal to me. It wouldn’t have happened without Wiseco.”
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Other companies also helped Rhine achieve his goal. Crank Works balanced the cranks. Millennium Technologies was in charge of plating the cylinder. Ceramic bearings from Worldwide Bearings got rid of the friction in the engine. Bill’s Pipes was instrumental in the build. Rhine used VP Racing T2 fuel, because he knew that increasing the oxygen content was necessary for a well-running system.
Race results don’t lie. Mike Smith went out and swept both motos in the 30+ Expert Class at the Wiseco Two-Stroke World Championship on the YZ250. It was a year and a half in the making. What’s most intriguing is that the fuel-injected Yamaha YZ250, just like his other one-off fuel-injected machines, will never be sold. Rhine doesn’t want the technology leaking out to the masses. It's obvious that Rhine is not guided by the almighty dollar, but instead through helping people and an intense fascination with advancing technology.
Rhine admits, “I don’t care what bike I’m working on. I see all the faults in every engine, whether it’s a two-stroke or four-stroke. I’ve built a lot of different engines over the history of my development company. I’m always looking for the pluses and minuses. At the end of the day, that’s what I’m hired to do. My job is to build things that people have never seen. It’s kind of stressful. I’m constantly trying to paint another Picasso, and it becomes so difficult. I get up against the wall in trying to find that next mouse trap. I love it!”
We can’t wait to see Nick Rhine’s next Picasso, because it will surely impress.
All photos courtesy of Mike Smith and Nick Rhine.