I/O RPM'S

[C YENSEN]

HEY I/O GUYS, I HAVE A 84 MERCRUISER 470, AND SHE IS OLD AND HAS HER PROBLEMS. I USUALLY RUN HER AROUND 3500 RPM AT CRUISING SPEED. MAINLY BECAUSE I AM AFRAID TO RUN HER ANY FASTER AND BLOW HER TOP :-/ IF ANYONE ON THE BOARD HAS THIS MOTOR, WHAT SPEED (RPMS) DO YOU CRUISE AT? I WOULD LIKE TO GET HER RUNNING FASTER, I AM JUST AFRAID I AM GOING TO RUIN HER. :'(

[C YENSEN]

I HAVE HAD HER RUNNING AT 3900 BUT SHE SOUNDS "BEST" AT 3500. ANYMORE THAN 3700 AND SHE SOUNDS LIKE SHE IS GOING TO COME APART.

[Airslot]

CY, I don' t know the specs on that motor but I recall it being fairly large bore, so it's not gonna like high RPM's. Probably best cruise around 3200-3500.

Airslot

[rb437]

Mines an '89 165 4 cyl which if I'm not mistaken is a later version on the same engine. Clymer manual lists full throttle as 4200 - 4600 rpm, but I agree with Airslot, engine seems "happiest" at 3200 - 3500 rpm

[C YENSEN]

ANY GUESS ON HOW MANY MPH THAT IS, I DON'T HAVE A SPEEDOMETER. ???

GUESS I AM JUST CURIOUS ::)

[bigshrimpin]

The 4 cly Volvo AQ130C has a max RPM of 5100 or 5500 depending on which model.

[C YENSEN]

I AM A MERCRUISER 470 MAN, DOESN'T CAPT BENT HAVE A 470? WHERE IS HE TODAY?

[revmax]

max rpm's on my v/6 4.3l is 4400-4800 if that's any help.

[rb437]

3200-3500 rpm and a 21 pitch prop gives me about 25mph

[Hammerhead]

3200-3500 rpm and a 21 pitch prop gives me about 25mph

Ditto to that. ICW speed limit is 25 here'bouts anyway.

[C YENSEN]

THANKS FOR ALL THE INPUT FELLAS ;D