hello i have a 250sx getting hard to start in the cold, changed the plug and cleaned the carb and didn't seem to do much work, the spark plug seems to be cover in a lot of carbon, can one point me in the right direction ? thanks

 

Make sure the choke works properly. Could be worth checking valve clearances and compression. If compression is below 90psi after valves have been set, it may be time to check for ring and bore wear, especially if it uses a bit of oil.

 

thank you sir this should help