went back to the pond again yesterday evening. tried the 3857/4 on my ts2, modded/ex. throttle k&b, turbo cut crank & head, james/oer modded 'pipe' sleeve (don't know the timing #'s, sorry), gadjetcraft pipe on a rek lower. got it set up & found needle with a tongue cut x-440, tips rounded down to 38mm. ran ok, not great, wouldn't unload enough. swapped to a VERY modded x-442, lots of backcut, ears both trimmed all along the leading edge & cut down to 37 mm. ran very well, double staged fairly easily. tried the 3857, would not launch - period! went from 1/4" above the sponsons to 1/8" below, in 1/16" increments. if it did bite, the motor fell off the pipe. tried lenghtening the pipe by 1/8", then another 1/8", no help.put it on my son's villain, basically the identical setup as mine, same results as mine, was a rocket! andy, any reason a 'sport' motor pulls this prop so well, and a piped motor doesn't seem to like it? my son tried it on his k&b, gold carb, equi 's' pipe, turbo head & crank, stock timing pipe timing sleeve, relieved on the outside for flow, stock lower - same result as me. runs great with the x-440 i tried on mine first. or, could it just be a ts2 & this prop? i know some hulls & props just won't work........