Re: How many RPM's is safe?
Shouldn't hurt it a bit. Marine engines are designed to run at higher rpm's for extended periods of time, they are built with higher quality parts than there automotive counterparts. I am able to run 4600 or so with mine as well, but always tune it back down to 4000 or below for fuel savings vs the 4 or 5 knots I'd get with the extra rpm.