RM250 RM 250 won't start

Those carbs are the worst for starting. Be sure the carb is clean, Fresh plug,Hold the throttle wide open and cycle the kick lever a few times slowly, Get it up on compression stroke, Take full kicks, not half kicks.
 
I have a 93 RM 250 that has a full rebuild.the water from my radiator leaked into my engine. The problem has been fixed I drained the oil and ran some new through it a few times I also tools the head off and cleaned the cylinder and made sure there was no damage but it still won't start I have around 180 compression good spark and fuel
did you get all the radiator fluid out of the crank area cuz this happened to my 07 rm125 and had to turn bike over so the pegs and wheels were on top and the seat on ground to drain out radiator fluid.tip bike upside down..take off cylinder...mine just kept drowning the spark out...will never start ...make sure theres no gas in the tank
 
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