Intake / Exhaust Port Chamfer Size For .030 Overbore

[superlund]

Recently had my '94 Evinrude 115 bored .030 oversize, I believe the ports need a new chamfer but don't know what size the chamfer should be. Just looking for a general place / idea where to start on a dimension, break the sharp edges with say .01 or .02 chamfer?? Appears like this could be quite a bit of work, but yet a critical step?<br /><br />Thanks in advance!<br />-Jim

 

[OBJ]

Re: Intake / Exhaust Port Chamfer Size For .030 Overbore

Yeah Jim....ya' need to break the sharp edges. These sharp edges can easily grab the aluminum the pistons are made out of and do some damage. Breaking them is easy. A half round fine file will do the trick. I usually break them till I can't feel the sharp edge no more. Be sure you don't leave any burrs behind and clean the block real good after yer' done.