Power shuts down when accelerating

[cr250-2000]

I have a 2000 CR 250 that was running fine and then just died when I was doing about 30 mph. It sounded like a ran out of fuel or fouled another plug. Fuel was fine, plug was oily, but did not restart. The next day I started it up with a new plug and now it will idle fairly well and rev up and run pretty good through 1/4 throttle but as soon as I accelerate it just bogs down as if has no fuel. Removed the carb and everything was clean as it could be. All jets are standard, needle jet in the second highest position. Run golden spect. at 32 to 1. Plugs are always oily, never paper color. I had the bike for two years and it ran great but now it just idles great any ideas what I should do next Thanks

 

[just_a_rider]

I came on here this morning for the exact same thing only it involves my 96 KX250. My prob is after a few hard laps mine acts like it's starving for fuel and it starts idling like you've turn the fuel off; high! I have checked the float level, cleaned the darn thing but I haven't checked to see if the silencer is clogged. My bike has always run great until I switched to Maxima castor 927 which is a great oil, lots better than Bel ray. The commpresion is great to a point that it slides the back tire when attempting to roll it off and I weigh 205lbs. I'm at a loss here.

 

[cr250-2000]

I have changed the needle jet position (tried all five positions)
without solving the problem. My main jet is 190 and standard for the Keihin carb is 180. Im guessing that I am flooding and killing the engine with too much fuel. Thanks

 

[just_a_rider]

Mine is jetted 158 main and a 44 slow, the air adjustment is a round and an half out, float is set to factory specs. I mix castor 927 @ 40:1 with regular gas. I use a #8 NGK Iridium plug, 8 bucks a pop, Boyensen reeds, procircuit pipe and silencer. I did take the end off the silencer today, pulled the packing out and rode it as hard as I could for about an half hour, I don't know if it had any thing to do with it but it did nothing like it was doing, infact it ran better than it has ever ran since I've had it.