Best prop for 2004 Chapparel 204 SSi 5.0 mercruiser

[workkyle]

Looking for recommendations for best prop to pull tubes and get on plane. My boat with current prop tends to porpoise if you trim the prop up just a little also. Current prop is aftermarket SS 14.25 * 19 3 blade. Gets 42mph max rpm 4300. I tried a 14.5*19 3 blade. It gets 45 mph @ max rpm of 4500. They both porpoise. The 14.5 seems to plane faster. Anyone know the factory prop specs? Any recommendations on best prop? Not my boat has 2 batteries and a subwoofer added in back. Boat came this way.

 

[QBhoy]

Hi. You’ll probably need to go down to a 17”. You’re not in even the lower rpm range with those props. A good 3 blade stainless 17” will see you right. You want to be in the high 4000’s with that engine. The porpoising will be a result of too much weight to the rear. If you are trimming it properly

 

[Stinnett21]

Check out Nauticus Smart Tabs to tame the porpoising.

 

[QBhoy]

Check out Nauticus Smart Tabs to tame the porpoising.

this boat shouldn’t have such issues out the factory and driven well, I’d suspect. More likely the heavy additional gear in the back and an effect of trim