A 16 x 8 on a 100? Those are perfect for breaking in a 1.50 or a 1.80 but IMO are a bit big for a 100. FWIW my 100 refused to pull a 16 x 4W when new, no amount of needle tweaking would coax the engine into running that paddle. Also, bear in mind that I am referring to the APC props and not a lighter, less efficient wood prop like a Zinger.