You say you need a male, but the photo depicts a female.
I haven't been into this part of the motor, but out of curiosity, went searching for a 17mm triple square male.
The largest size I found was 16mm and that was at Snap On. If they don't make a 17mm, I doubt it exists.
Are you sure this fitting is triple square and not torx or allen?
See the following thread.
http://www.peachparts.com/shopforum/showthread.php?t=123853&highlight=chain+tensioner+M103