Back in the 1990’s no one was really working on small performance four stroke engines, but the Powroll R&D department had a dream which turned into the first-ever CRF150.
The Powroll R&D CRF* project 150cc, water cooled, double overhead cam, four valve. Programmable digital ignition, flat slide smoothbore pumper carb. Built in over the winter of 2000, the engine was a used as a proving ground for new development ideas.
*We thought of the CRF moniker before Honda released theirs. Powroll’s CRF is a shortening of the names of the two engines used, CR80 and CBRF3.
Big Guys on Little Bikes
For years, fathers have borrowed and subseqently thrashed junior’s XR100. In some areas, the thrashing became so much fun that clubs and events were founded which were devoted solely to racing four stroke minis.This racing became popular with amateurs and pros alike. Businesses started building parts for this new market. Stock chassis were weak and broke under the stress. Chassis builders like BBR began to build high-tech frames which were stronger, lighter and better handling than anything else on the market.Fortunately for this niche of racers, Powroll’s line of products has always included go-fast goodies for the XR80 and XR100 (and now the TTR 125, DRZ/KLX 125 and Honda’s CRF150). Doubling the horsepower on these little beasts was easy for us, we’ve been doing it for years.Guy Cooper, Lance Smail, Rick Johnson, Jimmy Lewis, Steve Lamson, and many others have enjoyed the additional fun provided by Powroll engines. Although we build the fastest minis out there, minibike enthusiasts still wanted more.Many racers spent evenings in their garage concocting different setups, but everyone had the same dream. What if someone made a water cooled four-valve mini engine?When the YZ 400F was released, the bar was raised for all four strokes. Now everyone realized four strokes could be competitive (something Powroll knew all along!).
Minibike racing became more popular, and races like Langtown and the White Brothers Mini Nationals were getting national coverage from the magazines and television.
At the beginning of the new century, Powroll and BBR teamed up to create the dominant mini racers. In 2000, Powroll-engined BBR bikes won the Four Stroke Mini World Championship (Rich Taylor) and garnered the top 3 places at Langtown (Lance Smail, 1st; Timmy Wiegand, 2nd; Brad Hagseth 3rd).
In December of 2000, Powroll’s new R&D department began talking about a completely new mini. One that was designed from the ground up. A 2001 CR80 was purchased, and head parts from a Honda CBR F3.
(if photos aren’t showing above, go here)
In December of 2000, Powroll’s new R&D department began talking about a completely new mini. One that was designed from the ground up. A 2001 CR80 was purchased, and head parts from a Honda CBR F3.
Although the design was easy to imagine, the actual logistics of oil delivery to the head, cam drive and ignition mapping were complex. Fortunately our R&D guru, Pete Fisher, had the answers.
The chassis was ordered from BBR Motorsports, who were also provided with a mock-up of the engine for the modifications required.
Started for the first time only days before it’s debut at the BBR 2001 Mini National, the sound is best described as YZF-ish. Extremely fast-revving, with a sharp exhaust note similar to a miniature Formula 1 engine.
DIRT BIKE MAGAZINE JUNE 2001
Quoted from the article shown above…AMA to allow 125cc Thumpers in the 80 class?
“Following the F.l.M., the American Motorcyclist Association is expected to lower four-stroke displacement allowed in the 250cc class, from 550cc to 450cc for 2002. Also. 125cc four-strokes will be legal for the 80cc class. You can bet that Yamaha is developing a YZ125F based on its current YZ80 and YZF technology. We expect Yamaha to scrap the YZ426F in favor of a lighter, 450cc motor to meet the new rules and go toe-to-toe with the Honda CRF45OR.
Powroll guru Pete Fisher is developing a four-stroke minibike engine of his own, grafting a CR8OR-Expert lower end to a four-valve street-bike engine. Fisher used a water laser to cut one cylinder, head and cam from a four-cylinder 600 then fashioned a cam-chain system and new liquid-cooling spigots to mate the upper end to the lower. As for oil, Fisher is building a pump that works off of the coolant impeller.
Brown Brothers Racing already has a race-ready four-stroke mini, which is a hopped-up TTRI25 engine wedged into an aluminum-perimeter BBR frame with CR8OR Expert suspension, hardware and plastic. Lance Smail won Langtown so handily that Jimmy Lewis will be BBR/TTR-mounted this year. Currently a 150, the BBR bike would have to be returned to stock displacement if the AMA goes with 125cc as the limit. We’ve heard rumors of the limit being 150cc, but the AMA is likely to go with the F.l.M. standard of 125cc four strokes at the fall congress.”
Powroll History and Tech 