Which Props do I use

Ok Guys,

Since I need to change out the props with new I am making sure they are correct ones for the boat.

I am trying to figure out what prop size I should have? I currently have A2's but with the information I can find it doesn't seem correct. Other posts show A4's maybe even A5's.

23 Fishmachine
AQD40A 135hp
280DP 1.95 gear ratio verified by removing the top cover of the out drive and rotating the prop one full turn while counting the upper shaft rotations.

The boat seems to run fine but I don't know for sure if the previous owner Moo Fish didn't change anything.

Marc

Are you able to hit max rpm at wide open throttle? That will tell you more about prop size than anything else. My AQAD40A is rated for 3600 rpm.You should be the same but you should verify that. If you hit your target RPM easily or over rev, go up 1 size. Going up should change things by 150-200 rpm. You should be able to hit max rpm without the temp gauge going over 200. Was it your boat that ran to cold? Get that temp gauge verified before doing any testing.

I have 15 more HP than you and run A7 props on 2.30 gears. I know a guy that runs A5 props on 1.95 gear with my engine. I don't think you could spin A5's to max rpm with your hp.

Mike

Hi Mike,

Yes it was my boat that was running cold at idle speeds and trolling, replaced the thermostats know it stays at a 75C on the trailer I haven't had it out yet waiting to replace the props.

Anybody else have the same set up as mine? Curious as to what props they are running?

Marc