I know that this spring was when all the snow came. But most yrs aint that way. Riding in anything less than powder w/o a flap is a recipe for meltdown. ESPECIALLY for big lug tracks as we tend to throw that slushy stuff right out the back rather than bring it on around to the coolers.
I'll tend to disagree with this WHOLE post!
I've ridden my last 3 sleds without flaps (one boosted 153, one N/A 153, one N/A 141) I ride till July most years, this was actually my first year of the last 5 NOT riding that late.
Not sure if the newer M's are a bit less likely to overheat? Never ran my older sleds without a flap, so I've got no comparison.
I don't ride trail 99.9876% of the time, but I ride Corona pass here & there & I think it's about 5 miles to the top on the trail? Never overheated there or even seen the first temp light.
OH, and the snow ALWAYS comes in the spring. (er, no, no snow here in may, stay in Cheeseland!!!)
Btw if I rode trail I'd leave the flap on, it'd be just plain rude to ride without one with a Pclaw on the trail!