Questions about Prop and Trim on a 2009 Bayliner 195/5.0L

[torontochris]

Good day all, having some minor issues and hoping for some guidance.

First off, boat is a 2009 Bayliner 195 with a 5.0L Merc, 220HP. Current prop is 14x19 3 blade SS. ratio is 1:1.62

2 issues i'm having.

First, boat seems to take longer than I'd expect to plane. I know its a lot of weight in the back, but with that much power I'd think it wouldn't take so long. If I have 4 adults in the boat, i need to move one or two to the bow to get it to plane out without ploughing for quite a while.

Second, and maybe they're related. My trim seems to be trimmed too far up at max down. I start it all the way down and even staying this way, with 6 adults in i'm getting a bit of bounce at times on flat water. With one or two adults, if I try to trim up from all the way down, i can't trim much than a hair before again getting a bounce.

So, would a different prop help with getting on plane better? Can the trim be adjusted so its lower at max bottom and would that help with planing?

Any suggestions would be appreciated. I've been boating most of my life but on smaller boats and my last was a 17ft glastron with a 90HP merc, bit out of my knowledge base here.

Thanks in advance,
C

 

[Texasmark]

Long hole shot is the engine is struggling with too much load due to too much prop pitch....assuming the engine operation itself is in pristine condition. If your boat is a deep V with a goodly amount of dead rise at the stern, it doesn't pop out of the hole like your previous boat, especially if folks just love to occupy the "jump seats" adjacent to the engine cover at the stern.

Trim not tucking into negative degrees is also a problem with hole shot and porpoising...course on porpoising it's all about thrust angle, hull design, and velocity....to stop it, it's less trim angle or more velocity. Mercury advertises their outboard engine PTT runs from -4 to +75* in the Tilt ,low rpm (<2500) function and 0 to +20* when under higher rpms in the Trim mode. Can't find data on Mercruiser specs. No idea as to their range.......in the search for whether or not your trim is malfunctioning, or it's something else. If you get back on here and ask the question, there ARE folks that can help you with that.

You didn't give your rpms or speed at WOT with your 4 person load. Back to the hole shot.....running some numbers on go-fast prop slip calculator, if you were hitting 4800 rpms (just a guess...no idea as to where your engine rpms are rated) at WOT rpm and your corresponding speed you'd be running 42 mph with a 20% prop slip, I'd expect something like that with a deep V at the stern with lifting strakes along the hull. 10% which one would expect with a flatter transom area bottom, you probably achieved with your previous boat, would run you on up to 48. Running 48 and 4 folks, even with a flatter transom area, like </=12* dead rise at the transom you should have the ability to control porposiong.

So, on the prop and engine performance, if you are running at the top end of your engine's operating range, and your engine is in fact putting out 220 hp, and getting a good hole shot your pitch isn't too high. If you are having a slow (hull shape, ability to trim properly, and load related as stated) hole shot and can't get to your max rated rpms at WOT you have too much pitch.

 

[Nextelbuddy]

i just went through this with my 5.7 and 14x19p. i tried changing props with worse results but in reality i jumped the gun with trying to change props. my boat with the 14x19p prop was only doing 35 MPH @ 4100 rpms and that was a struggle.

turns out my engine needed some maintenance, the previous owner of my boat said they replaced the engine so i never checked anything. when i finally checked, one of my spark plug boots on the spark plug for cylinder 6 wasnt even clipped in, the boot was just resting on the tip and then cylinders 2 and 4 were reversed at the distributor cap so in reality i was running on 6 cylinders terribly and thats why my boat was struggling to get to 35mph and not reaching my max rpms of 4800.


i replaced my cap, rotor, new plugs, new wires, new fuel filter, made sure all plugs were connected properly and now my boat gets out of the hole really fast on plane and has no problem getting to 47 mph at 4800 rpms with a 14x19p.

in fact i plan on going back to the original prop the boat came with from the factory which was a 13.75x21p to get some more top end now.


so please get a base line of your engine in regards to your max speed and what the rpms are showing at that max speed and that will tell you how healthy your engine is currently.

 

[Texasmark]

Glad you got that solved.

 

[QBhoy]

100% certain here that a 19” prop isn’t underpropped. Look somewhere else for your issue...unless you are comparing the hole shot expectations to a jet ski or something.