My rm 250 has no spark i have change the stator,cdi box and coil but still no spark

check your ground wires,could be a bad coil lead to the plug,a bad coil in the stator,a bad plug?try these things first

its not likely the cdi if you have any spark. check the cable, coil and spark plug cap (over looked a lot!) for the correct resistances.

chec battery-must always be at 12.6volts-any lower and bike wont function--inspect connections for corrosion--also make sure carb and fuel delivery are correct

The Voltage From The Stator To The CDI Should Be Around 40 Volts(AC) At Cranking Speed. Be Sure Your Meter Is Set For (AC) Not (DC). The CDI Changes The (AC) Input Voltage To (DC) Output Voltage To The Primary Terminal At The Coil. An Electrical Shock Hazard Exist If Stator Voltage Is Checked With Engine Running. Always Perform This Test At Cranking Speed (R.P.M.) For SAFETY. 120 Volts (AC) Can Be Present With Engine Running.

I'm having the same problem with my Kazuma falcon 250. No spark, the stator shows good ohms and I just replaced the CDI box and still nothing. I'll check the kill switch and reverse override.

what comes out of CDI box? if you have it going in it is rectified and more will come out. If not change CDI

If it ran before, I would double check your electrical connections. Its more likely you didn't get a connector pushed all the way together or left off a ground wire. The ignition coil specs are generally 1 ohm or less on the primary (small Wire) side, and 5K-10K ohms on the secondary (spark plug) side. Each side should be tested to ground. Pick-up coils are typically open or really large ohm reading in Megaohms normally and around 100 ohms when the magnet on the flywheel passes by. there is no way to test the CDI box other than putting it on a know running bike or getting a known good CDI and putting it on your bike. Double check that the spark plug cap is secured to the high tension lead as well. Testing the stator is a little more complicated, but a quick way is to close the gap on an old spark plug to about 0.010" and see if there is a week spark. If so, the stator will need to be replaced.

I have a 83 DR 250 and i'm not getting enough voltage to create a spark, all I can suggest is that you check your battery and make sure its at full flavour. Check and see if you are getting any voltage prior to the ignition coil (should be 18-35v). If you suspect battery then try clutching it as the alternator moving faster might give you enough to get her going. Also check all your connections and earths. Earth wires are often overlooked and can cause you just as many problems as the actives. So give that a go and get back to me mate. Cheers

could be stator or the coil or cdi box

see if you have ac voltage from the stator coil when cranking motor.if you do,try swiching cdi box out.also check for power to ign. coil.