Mxu150 will not take any throttle till fully warm.

[Rpm90001]

Hey guys, first post here for me.   I bought my son a showroom condition 2008 (I think) mxu150 with 120 miles on it.  Bought from close friend who bought it new. 

I have a problem that he said it alwasy had.   I can start it fine, but it will not take any throttle till fully warmed up.  I have to let it idle for 8-10 minutes before I can give it throttle.   Fully warm its total fine.

Anyone else with this issue?  Ideas?  My garage is heated about 65 deg, I don't think I should have to let it warm up more than a minute befor riding.      Thanks for any help,

Geo

[Alligato]

How's the plug look?

[BettinANDlosing]

Clean the carb and you'll be golden

[Rpm90001]

Plug looks new, but I will replace it.  If carb was dirty, why would it run perfect warm? 

Thanks,
Geo

[BettinANDlosing]

The idle jet is plugged, once it's warm it doesn't need as much fuel and runs ok. 99.9% of the time dying when giving out throttle is plugged idle jet.

[Rpm90001]

Swapped out the plug, issue is 95% gone.  Slight stumble for e first 2 minutes then all is good.  Old plug looked good..  Gas is a year old, (didn't knowthat till this evening). Will drain and fill with fresh tomorrow.   Not a bad little machine.  Thanks for help!   G