'X Games' Star Jackson Strong -- Nixing Snowmobile Freestyle DISHONORS Caleb Moore

"X Games" star Jackson Strong is calling out ESPN for canceling an upcoming snowmobile freestyle competition -- the incredibly dangerous sport that cost Caleb Moore his life 3 weeks ago in Aspen.

Action sports athletes have been mum since ESPN pulled the plug on the freestyle demo -- scheduled for next month in France -- but Jackson tells TMZ he thinks that's a big mistake ... and not at all what his friend Caleb would want.

Jackson, aka "Jacko," says ... “Personally, I don’t think he would have been impressed if they were to cancel the contest. Anyone in 'X Games' or action sports knows the risk they are taking.”

Caleb died on Jan. 31 from injuries he suffered while attempting to backflip his 450 lb. snowmobile. ESPN says it's continuing to review snowmobile freestyle ... but some critics think it should be eliminated altogether.

21-year-old Jacko had his own 'X Games' brush with death while trying a freakish move called "The Jack" (below at 1:00) -- and admits there are huge risks when stunts go wrong ... but "everybody is pumped when it goes right.”