buying a prop

[jlds913]

Im looking to buy a new prop for my 985 Johnson gt150 engine, the engine is in good running shape but at WOT im only hitting around 4200 to 4500 rpm. The engine is on a 1985 Ranger 372v bass boat. Top speed is about 45 mph. Right now the engine has a 24 pitch. I was looking to moving down to a 21 pitch does this sound about right? Also what about diameter of the prop? Not sure what to get.

 

[fireman57]

Re: buying a prop

You are probably in the ballpark but you might just have things set up wrong. Post this in the prop sections and the pros there will be more than happy to help you.

 

[jlds913]

Re: buying a prop

Thanks, Can someone move this for me?

 

[Blazinmonkey]

Re: buying a prop

are you sure its the prop?

something sounds off...

how long have you had this boat?

 

[jlds913]

Re: buying a prop

About 3 months. I have checked all the linkage and everything seems correct. Tested compression again and got around 115psi on all cylinders. Only other thing I can think of is the vro was bypassed with a small electric fuel pump. Maybe not enough fuel?