35thls1ss19

Hey guys, i have read a lot of posts and realize my 1.36 gears might be holding me back?

I know i know i should put a bravo on but anyway....... ever since i have owned my boat i never get rpm out of it. Compression test is great blah blah been threw the motor the last 2 years. Anyway the only thing i can see is that i have 1.36 gears. I am spinning a 19 pitch prop and only getting 3600 rpm. I was wondering if i can change my gears to 1.50 and spin a 21 pitch prop maybe get more rpm and more speed?

i have read alot of other formula 223 ls guys getting 60+ spinning a 21 pitch prop. but with bravos, so a assume its 1.50 gears. I am getting 52 with my 19, and i know to get more rpm i can drop to a 17 but i would get less speed?

blue thunder

Per my estimates you are only getting about 40mph, is that about right? Anyway, the 1.5 gears would only bring your rpm up to around 4000rpm with the 19p. You did not mention what the engine is. That would help. If it is a 454, you have low power from the engine for sure.

Griff

Changing from 1.36's to 1.5's will only gain you about 600rpms using the same prop. I think you might have other issues.

bigblue

Maybe its the lake water! Or time for a re-power

fireboatpilot

+1 on other issues. Will it rev in neutral with no load? Need more info on engine specs but I don't think it's prop related and definitely not gears. fuel or timing issue?

lakematdude

Also what type of sterndrive do you have?

What Type of engine do you have?

What is the year of the boat/engine/drive?

What Model / Brand (manufacturer) of propeller are you running?

Also If you happen to know, what is the diameter of this prop?