I have ridden it in the most demanding trails we could find ,in places like some of the more dchallenginfg trails of keysville cali, where a trials bike is perhaps a good choice..lol
have also have put pretty seriuos time on it,,in the big dunes of glamis,,with a paddle..
and never have had an overheating problem..in any riding sitiuation.
like all 4 strokes, or even some 2 strokes ,
if you sit still, at idle long enough ,then you can get it to overheat..
but if moving at all ,even on really slow technical trails it will be just fine.
The junior X, utilizes the CRF250 radiators,and shrouds ,
so it has very good cooling capacity..
also we do recommend engine ice,although regular honda coolant works fine.
I have run temp gauges on this model several times at glamis,jawbone, keyville ,gorman big bear cali,,in a lot of rough mountain terrian,
in the tighter woods trials of the midwest.,and places with a lot of tight single track,,
if anything the average running temps on a JR-X tend to be on the cool side,,180 to 190 F...
hope this helps!
AJ Waggoner
Operations and Project Manager
Service Honda
Kawasaki/Yamaha/Suzuki