Motorcycle Repair: performance, silk purse, wheel alignment

Question
hey mike i have a 82 cm250 that runs great.  i was just wondering if there was anything i could do to make it go any faster.  with a tail wind going down hill i get it up to alomost 70, but on the flats 55mph or so is all i can get out of it.  anything at all would be awesome.  thaks mike
ryan ATX

Answer
Ryan, it is probably cheaper to buy a bigger bike than to try to make a silk purse (250 Ninja) out of a sow's ear (CM250). The basic bike contines on as the 250 Nighthawk and the 250 Rebel, with barely any increase in power than what you have now. The afore mentioned Ninja 250 will go about 100mph, all tucked in, but they tend to be fragile when thrashed constantly.

You might check the spark advancer, located behind the ignition plate, to see that it is still advancing and retarding. Verify the spark timing with a timing light.

Adjust the valves to .002" COLD on both intake and exhaust sides on their respective compression strokes. Be sure that the air filter is clean. Things like tire pressure, chain adjustment/wheel alignment will all add-subtract speed depending if they are set to specs or not.

The only way to make more power is to raise the compression ratio, install a higher performance camshaft, try porting the head and installing a slightly larger carburetor. Free breathing mufflers may help it a bit, but will probably make a lot more noise than power.

They really weren't designed for high power/performance and trying to squeeze out more is pretty futile, for the most part.

Bill Silver