It should be about 63mm long. I printed it on my 5th gen maker bot with 2 shells 10% infill and .1 layer height before I posted it and it worked great. See if maybe those settings help you.
If anything if maybe go 3 shells though to make sure it's air tight. Also check to during the print that there is no excess stringing in the air channels or chambers that might disrupt flow. Hope that helps.