Motorcycle Repair: 250 yz, bill silver, expansion chamber

Question
I got Yamaha 250yz 2001, i did't know how much power it has,
my question is can it possible that the thork on the bike can be reduce,when i ride it feel like it wants to do a wheely,

Answer
Daniel.... you bought a MX race bike, not a trail bike. A quick search on the web showed that Yamaha and perhaps other aftermarket companies offer a heavier flywheel that will reduce the quick hit of the motor. Check Yamaha dealer or accy parts houses for application. You will need the special rotor puller tool, to remove your old one, however.

Other ways to tame the monster could be to add slack to the throttle cable, so it doesn't open all the way. Repack the silencer with LOTS of fiberglass to reduce the exhaust flow. Reducing the compression through adding an additional base gasket, may help.

I am really not a Yamaha guy, 2 stroke guy or MX 2 stroke guy, so these are general guidelines. Other sites, that specialize in MX tuning may have other options for you, including a differently configured expansion chamber that is tuned for a different power delivery.


Bill Silver