1st Prop Test!

[scott8058]

I have a 95 Bayliner 2050 ss with a 355 and an alpha 1 5.0 out drive. Currently i have a 15.5 x 19p stainless steel prop on there and it runs low 50's at around 5200 rpms. In my opinion that seems a little high, and ive heard that its the alpha 1 i need to worry about. I switched the prop today to a 21p aluminum and taking it out tom, will this lower my rpms? any change in top end? or is 5200 ok for that set up? This is my first boat and im just trying not to tear it up lol!

Any help is appreciated, thanks

 

[Maclin]

Re: 1st Prop Test!

As you suspect, 5200 rpm is high. The 21p should drop you down to 4800-4900 and keep the same top speed. If it can still get to 5200rpm (with higher top MPH) then that engine may be able to turn a 23p in that boat, just doin' a little bench-proppin'.

 

[scott8058]

Re: 1st Prop Test!

Thanks, if it does turn the 4800 is that a safe operating range or would i still need to lower it? And i understand like you said doin a little bench proppin, just looking for any advise! oh and what size nut holds that prop on, i assume they are standard? i don't have a socket big enough and have to go get one lol

 

[Maclin]

Re: 1st Prop Test!

I would stay below 5000, 4800 is about perfect top end for that drive.

 

[scott8058]

Re: 1st Prop Test!

Well i guess we'll see what happens tomorrow, ill post the results and thanks for the input.