Rpm and prop Merc 470

[v65stiffie]

Hey all,<br />It's been a while.<br />I need to upgrade to a stainless prop on my Crestliner C185 with 470 I/O (fiberglass, open bow).<br />My 19 pitch prop (2+ repairs) shoots right thru 4200 rpm and keeps climbing. At 4500 Rpm I back off even tho it is still climbing. 4200 RPM = 34 mph GPS<br />I need the hole shot to be strong (pulling people up)<br /><br />Is 4200 the correct max running RPM for my '84 470?<br />Should I got to a 21 stainless?<br /><br />I did a search but got more confused.<br />Thanks for the help.

 

[v65stiffie]

Re: Rpm and prop Merc 470

Searched further and got my answers.<br />4600 rpm MAX!<br />I'll throw a 19 stainless on it and enjoy the season.<br />Thanks!<br /><br />(I have the 4" cooling installed and bracket for alternator)

 

[Bob_VT]

Re: Rpm and prop Merc 470

Glad we could help!!! <br /><br />I have a 470/170 too!<br /><br />Bob