ASK THE MXPERTS: 2007 HONDA CR250 TWO-STROKE QUESTIONS

MXA’s 2007 Honda CR250.

Dear MXA,

I am a late-20s professional practice rider. Unfortunately, I don’t have a whole lot of money to spend on a new bike. Because of this, I recently purchased a used 2007 CR250. I am unable to find the official 2007 CR250 Motocross Action race test on the internet. I was curious if you had the best suspension settings from your 2007 test?

Honda rode high on the hog during the ’90s with CR250 sales close to 10,000 units. The CR engineers began to think that they were infallible–and, in the process, they gambled on blowing the competition away with a totally new engine design in 2002. Unfortunately for Honda, the all-new revolutionary case-reed engine, with its electronic power valve, traction control ignition and high-tech carburetor, never lived up to its promise. Sales dropped when Yamaha and Suzuki’s 250 two-strokes got better and plummeted when four-strokes took over (although there was some solace for Honda in the fact that CR250 riders became CRF450 riders).

THE BEST TRAITS OF THE 2007 HONDA CR250

Handling: For those of you too young to remember the glory days of Honda handling, suffice it to say that Jeremy McGrath loved his 1993 CR250 so much that he never raced a 1994, 1995 or 1996 Honda during his time at Team Honda. And, when the first aluminum-framed CR250 came on the scene in 1997, Jeremy rode it a couple of times and bolted from the Honda fold. Jeremy was astute. The ’93 chassis was awesome, and the ’97 Delta-box was gruesome. After ’97 Honda spent more money on frame development than any of the four motorcycle manufacturers and, in the process, massaged the bugs out of the aluminum frame making a bike that was excellent at turn-in, rock steady at center-out and clean on the exit.

Quality: Honda had the best metallurgy, quality control and reliability. This was a bulletproof machine.

The case-reed CR250 suffered from a weird low-to-mid transition. It was famous for going wah, wah, wah when it should have been pulling.

THE WORST TRAIT OF THE 2007 HONDA CR250

Jetting: This was a mystery machine. It’s not that we couldn’t get the jetting to be spot on, it’s just that we couldn’t keep it there for more than three hours. Every day we spent with the CR250 was an adventure in brass. We eventually learned to accept that today’s lean jetting would be tomorrow’s rich jetting. Even the slightest change in one direction or the other would send the CR250’s jetting into gurgle, diesel and ping land.

MXA’S RECOMMENDED 2007 CR250 JETTING SPECS
Main Jet: 420
Pilot Jet: 38 (40 stock)
Needle: 6DGY-26-65
Clip: 2nd from top (3rd stock)
Air screw: 2 turns out
Note: Honda jetting is rich on the bottom, but lean everywhere else. When you lean out the bottom, the CR’s pinging gets more ominous. On a daily basis, our best solution was a dose of race gas, a leaner pilot, and lots of fiddling with the clip position.

WHY DID THE 2007 HONDA CR250 HAVE SUCH A WEIRD POWERBAND?

No mystery. In 2002, Honda dropped their trusty reed-valve, piston-port design for a case-reed configuration. This was a radical engine choice for Honda and one that had previously been deemed best suited for 125 two-strokes. But Honda gambled on the rock ’em, sock ’em benefits of shoving the carb throat directly into the cases (instead of into the cylinder). The best guess for why it didn’t work was the the crankcase volume was too large to get the proper charge up the transfers at low rpm. Honda never fixed it—they just stopped making it!

MXA’S RECOMMENDED 2007 CR250 SHOCK SETTINGS
Spring rate: 5.2 kg/mm
Race sag: 105 mm
High-compression: 2-1/2 turns out
Low-compression: 7 clicks
Rebound: 7 clicks
Notes: Make small (about 1/8th turn) adjustments to the high-speed compression. Its standard setting is two turns out (and then an extra twist to align the punch marks). We had our best luck going farther out instead of in on high-speed.

MXA’S RECOMMENDED 2007 CR250 FORK SETTINGS
Spring rate: 0.44 kg/mm
Oil height: 384cc
Compression: 10 clicks out
Rebound: 14 clicks out
Fork leg height: 5mm up
Note: The 2007 CR250 forks are 7mm longer than the CRF450 forks because they are the forks that were designed to go with the 20-inch front wheel (which Honda still offers as an option).

 

 

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