2006 Honda CR250R - Elementary Tuning - Dirt Rider Magazine

Since the reintroduction of the case-reed motor, the Honda CR250R has gone from a class favorite with "the Motor" to a powerhouse with fewer fans. On the dyno and at full throttle, the motor sings. On the track its quirky throttle response, finicky jetting and various noises from power-valve rattle to detonation really put a sour taste on an otherwise sweet ride. Now that Honda has announced the 2006 CR250R is basically the same bike, these problems will affect the '06 version. Wanting to fix the flaws, Dirt Rider set out to dial the CR250R as best we could, and here's what we learned.CR25OR Pipe Science
Our overall favorite was the Pro Circuit for gains in power and delivery. It gives the bike a lot of snap yet is still smooth enough to roll it on out of turns without the bike spinning violently. But the Pro Circuit muffler was raspy sounding and too loud for our tastes, so we actually preferred running the stock muffler. Next in line was the FMF Factory system, which mirrored the performance gains of the PC setup yet was slightly smoother in overall delivery, and it tended to allow a bit more overrev. Its muffler, the Shorty, was similar in sound and performance to the stock piece. Our third favorite would be the stock pipe, which seemed to do just what a stock system should: fit a wide variety of riders and have a very smooth power spread while still being exciting in the low and mid. The stock muffler does a really good job.We also sampled an FMF SST pipe with a Ti 2 muffler, which seemed to make the midrange really come alive but tended to hurt the power on the bottom and top to accomplish this. It was also necessary to rejet specifically for this pipe; it tended to be very finicky about jetting, especially the needle position from track to track. It also increased detonation. For kicks, we threw on an FMF Gnarly with a Q muffler. It gave the bike a smoother and longer pull and really deadened the hit, making the bike much more tractable for, what else, off-road conditions. Plus, the Q really took a dent out of the sound, especially right at the crack of the throttle.Exhaust Price List
Pro Circuit pipe: $229.95
Pro Circuit muffler: $119.95
FMF Factory Fatty: $249.99
FMF SST: $249.99
FMF Gnarly: $229.99
FMF Shorty muffler: $119.99
FMF Ti 2 muffler: $149.99
FMF Q muffler: $159.99