prop help

[waterdawg69]

My 18 ft Celebrity with 175hp alpha one, at WOT it does 40mph at 4000 to 4200 rpms on my gauge at 4200 its right at the yellow mark and 5000 starts the red (like temp gauge) is it ok to be in the yellow or not. i think my boat could go alittle faster Right now its got a alum 21 inch prop 3 blade.

 

[steelespike]

Re: prop help

Your ok in the yellow 4,200 is most likely the lower end of reccomended max rpm.You should confirm your tach is accurate.You may be able to borrow a
shop tach or get a tech to check the rpm.You should also try to get a gps speed.It appears you can't go for more pitch as your probably at the bottom of you rpm range now.Going down to a 19 would put youy at about 4,600 which may be the macx reccomended rpm. Is the prop in good shape?Is the motor in good tune running on all cylinders?It would seem a 18 ft boat with a 175 hp would run easily over forty.

 

[waterdawg69]

Re: prop help

the engine is in fine tune nothing wrong with it, the prop is no bent or anything just the factory paint on the prop is flaking and coming off. I called Sea Ray dealership who deals with merc engines says i should be at 4600-4800 but i don't know if this would be correct or not. thanks for the help