I recently purchased a Ranger 350-V with a 150 HP Merc 5751409 on it. I know the prior owner and he sold due to a torque issue.
During a tournament the motor was running well and when he fired up to move to a new location he wasnt able to get on plane. He was running a 23 Pitch High Five prop and the motor was waddling around 3500RPM.
He took the boat and motor to a local marina and had an array of diagnostics completed. The mariner kept the boat for over a month and completed two lake test with no luck.
The prior owner decided to put on a 20 pitch high five and was able to get right on plane and run appropriate RPM's. However he lost his top end speed.
I would appreciate any feedback if anyone has ran into an issue of this sort.
I don't understand. If the performance was "normal" with the 20 prop, it must have been way under with the 23. Like 600-700 rpm under. So he was not propped correctly with the 23. What the the marina finally say? Couldn't find a problem? Found a problem but couldn't fix it? Did they pinpoint an engine issue or a prop issue? Since you say it was running well and THEN had issues that indicates an engine issue. Why changing the prop was part of that equation is weird. If the engine was not running properly then a prop change would just add another variable.
Is compression good throughout? Proper operating temperature? Proper trim position? Lots of causes here and we'll want more info to help.
I will say the High Five takes some guts to turn. I tried one in the same pitch as my 3 blade and lost 400 rpm instantly.