06 290 Sundancer prop replacement

[Boz007]

So my boat has struggled to get on plane ever since we bought it a few months ago. I have twin 5.0s with Bravo 1 drives. I'm not concerned with top end and would just like more thrust out of the hole. Current props are 14.50 x 17 Vengeance RH and 14.50 x 17 Vengeance LH (according to sea ray's site). Would swapping to a 4 blade prop help and if so, who's?

 

[Lazy Daze]

4 Blade would help a little bit, but you should be getting a pretty good hole shot with what you have there. Granted, it's not a little 18' runabout, but as far as cruisers go it should be pretty decent. Before you go and buy new props, that really may just be a band-aid, make sure other items are taken care of.

For example...

-- Is the bottom clean?
-- Tune-up items
-- Drives all the way down on take-off?
-- Using your trim tabs?

What is your top end speed (GPS) and RPM, with a minimum load?

Also, physically verify the prop pitch by looking at them. Don't assume that a previous owner didn't go and put something else on there.

 

[KnotEasy]

Did the boat "struggle" to get on plane when you sea trialed it ?

 

[Boz007]

4 Blade would help a little bit, but you should be getting a pretty good hole shot with what you have there. Granted, it's not a little 18' runabout, but as far as cruisers go it should be pretty decent. Before you go and buy new props, that really may just be a band-aid, make sure other items are taken care of.

For example...

-- Is the bottom clean?
-- Tune-up items
-- Drives all the way down on take-off?
-- Using your trim tabs?

What is your top end speed (GPS) and RPM, with a minimum load?

Also, physically verify the prop pitch by looking at them. Don't assume that a previous owner didn't go and put something else on there.

The bottom is indeed in need of cleaning and paint. It's on the list for the end of the season.
New cap and rotor, plugs and wires.
Drives are all the way down.
Tabs are not currently working (new pump but I need to pull the boat to replace the o-rings in the trim cylinders as they leak like a sieve). I know these will help but I need to trace down a bigger issue before relying on the tabs.

Looking back at the survey, these are the numbers that the surveyor wrote down. 48-18314 17P and 48-18315 17 P

When I say struggle, I mean she hasn't planed in weeks. She has of course been on plane several times before (though it sometimes takes a passenger or two on the bow to help). One motor is not going to full rpm's and stops at 3500 while the other gets to 45-4600 no problem. I initially thought it was an engine problem but a quick check by a mechanic and he doesn't believe it to be. Everything runs smooth and clean but it won't full rpm's. No missing or knocking. Which is what brings me to a possibly damaged prop. I had been considering new props anyway. I suppose that would've been useful info to start with but I was in a rush lol.

Did the boat "struggle" to get on plane when you sea trialed it ?

The boat was kind of neglected before we bought it. It had sat, I believe, for a couple years unused. So we knew going in there were going to be a few issues and I'm perfectly ok with it. The price was right. I've spent the summer enjoying it and fixing it and it's been a terrific learning experience for me.

 

[Ididntdoit]

Agree with above - you don't have a prop problem.......if cleaning the bottom doesn't do it, its an engine problem.....start with the one that wont get past 3500rpm - If all the obvious checks out (fuel pressure, tune up, no codes, etc) then do a compression test....sitting for a long period of time unused is recipe for disaster...

 

[Lazy Daze]

OK, #1: Get the bottom clean. Gotta start with that. Then, if still having a problem, take a look at fuel pressure at the rail. At that point, it really could be any number of things - fuel filter... clogged lines, pressure regulator, etc... compression... fouled injectors... old fuel that has varnished... It can be a long list of "possible" things and you don't want to start replacing things "hoping" it will solve the problem. If you're not comfortable doing some of these things, it would likely be money well spent to have a shop spend just a couple hours on it.

 

[LG111]

Based on what I have read, your mechanic said your engine is fine. The other reaches full RPM which has nothing to do with a dirty bottom. If it was a prop issue your RPMS would only be off a few hundred off. The boat sat for a some time, did you pull the outdives to inspect? The bellow could be full of water and gimble bearing could be rusted to the shaft, creating friction and over working the engine...?

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