Need help with prop

[79 delta runner]

I have a 1979 delta bow rider with a 305 inboard and 898 mercruiser and trying to figure out right prop for it. Currently the boat has a 14.5" 4 blade 16 pitch prob. Seems to run ok but top speed is only around 30 and 35 if I trim up on smooth water. I'm running around 4000 to 4500 rpm. Dont know much about the boat bought used. Motor runs strong no issues bogging down just seems like might be a little slow for it. Would appreciate any help or advice.

 

[79 delta runner]

Re: Need help with prop

I have a 1979 delta bow rider with a 305 inboard and 898 mercruiser and trying to figure out right prop for it. Currently the boat has a 14.5" 4 blade 16 pitch prob. Seems to run ok but top speed is only around 30 and 35 if I trim up on smooth water. I'm running around 4000 to 4500 rpm. Dont know much about the boat bought used. Motor runs strong no issues bogging down just seems like might be a little slow for it. Would appreciate any help or advice. Thanks

 

[steelespike]

Re: Need help with prop

Can you pin down the actual rpm and speed better?
What size is the Delta? Unless it is a monster of a boat your prop
seems small and your speed ploddingly slow.
Is your speed by gps?
There are 4 Delta boat companies listed.
Maybe Delta Manufacturing?

 

[79 delta runner]

Re: Need help with prop

It's a 17' bowrider it's by delta manufacturing. The speed was from speedometer the rpm's were 4500 and max speed was 35 and that was with trimming up motor and calm water. The boat has stainless trim tabs and plains out good just seemed to me was kinda slow for size and motor but wasn't sure if normal for that year and set up and prop. Also the prop is a composit prop another reason was looking to upgrade it.

 

[79 delta runner]

Re: Need help with prop

It's a 17' bowrider it's by delta manufacturing. The speed was from speedometer the rpm's were 4500 and max speed was 35 and that was with trimming up motor and calm water. The boat has stainless trim tabs and plains out good just seemed to me was kinda slow for size and motor but wasn't sure if normal for that year and set up and prop. Also the prop is a composit prop another reason was looking to upgrade it. Having trouble finding info for it all marinas books don't go back far enough