2004 CR250R Won't Start

My bike is killing me.  Bought bike barely used, rode it for a year, Son got really sick in the hospital for 7-1/2 weeks last summer so bike was in storage for a year.  Mixed new gas and it started up second kick and then revved up to a very high idle so I had to kill it by putting it in gear and letting the clutch out with the brakes on.  I figured it was a carb problem after sitting for so long so I pulled off the stock Mikuni TMX 38 10A (it has stock jetting except the Pilot, 40 Pilot Jet/420 Main Jet/Stock Needle on 2nd clip).  I disassembled the carb and soaked the body in Berryman's Carb Dip Solvent overnight, washed it out in the deep sink and blew out all the passages with compressed air.  I cleaned and re-oiled the air filter.  Validated that I have flow out of the fuel tank to carb.  I reassembled the carb, replacing the Viton needle and seat, float bowl oring seal, pilot jet 32.5(new), and main jet 420(new), Air/Fuel screw 1-1/2 turns out.  Bike wouldn't start at any A/F screw setting.  Pulled the plug, it had a BR8ES in it that looked, as expected, based the on richer jetting it was pretty black.  Replaced with a new BR8EIX.  Pulled out my handy-dandy spark tester and it had a big fat blue spark.  The motor has very few hours on it and has plenty of compression.  Still won't start.  Inspected the Vforce V3 reed valve block.  No reeds chipped.  I figured maybe the high idle and rich jetting on the Pilot Jet may be due to a leaking left side crank seal so I replaced the crank seal and went to the stock 32.5 Pilot Jet.  Still won't start.  I shot ether in the airbox.  Still won't start.


I am at a bit of a loss right now.  Here is what I am gonna do this weekend ANY ADDITIONAL IDEAS WILL BE MUCH APPRECIATED!


Check Float level on Carb

Change out the reeds

Replace clutch/water pump side crank seal

Clean fuel tank valve screen

Replace fuel tank breather hose

Compression check


Thanks in advance for any help you folks can provide.  Never been so stuck before.



start with the comp test.


also remove the exhaust and visually look at the piston and cylinder walls.

Go back to the spark.. Just because the spark tester showed it working once, it might have a break in the coil wire somewhere, and worked in that specific position.. Even the plug, I would grab a second new one to eliminate the chance that the new plug is no good. Check for the spark right at the plug tip, by resting it on the head, maybe the cap is no good.. Also check that the plug is seeing fuel when it's kicked over by smelling it for fresh gas in the cylinder

Good call on going back to the spark.  Coil/plug wire assembly appears to be bad.  Got one on order from RMATV

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