Max Rpm 454/420
 

My buddy has a 34 Scarab. The boat had 24P bravos on it when he got it. Turned 4000 Max. Put some 19P Rev's on it, now hes at 5000. He only gained maybe 1-2 mph. He is concerned that he is hurting the engines by running 5000 vs 4000. he wants to prop them around 4600.

I told him lugging the engines can do more harm than running the recommended max rpm of 4800-5200. He's gonna try some 21P props next. he runs around 58 in fresh water at 5000. Thoughts??

Run them 5000-5200rpm. Lugging is no good.

bl

agree