Just purchased a 2007 key west with 1807 miles on it for my son. have put roughly 40 miles on it. It has been running poorly. I changed the gear case oil, cleaned and reoiled the air filter, and changed the plug with a new properly gapped plug. it starts and idles fine (although low) and runs fine for a little bit each time it is ridden. As it warms up it begins to stumble and bog at higher throttle settings. I drained the gas tank and replaced with new fuel and removed and cleaned the carb. It ran fine for a few miles and again is bogging and stumbling at higher throttle settings. If it begins to bog, if you lessen the throttle it catches itself and continues to run but if you hold that throttle setting it bogs the engine and begins to run down.
Any idea's what else to look at to cure the problem.
Thank you for your help.