Operating concerns-gctid821811

[6549vincent]

Hello everyone. I'm new to owning a bigger boat and have some questions. I've asked around and get mixed answers so I am a little confused. I just bought an 87 bayliner 2550 and my first descent trip out my engine coupler and hub went. Not sure what happened. Mechanic says it had wrong prop on it so now it has a 15 1/4 ×15 on it. I'm very concerned and don't want to spend another 2k. To have it fixed again. One of my concerns is operator error. When I had it out that day I had the i/o tilt full down and didn't use the trim tabs. Could this have been an issue? I don't have a trim guage either. My mixed answers are some say leave tilt full down and use trim tabs others say use i/o tilt to trim boat and only use trim tabs for listing. I would have much rather spent this money on a new canvas. I got the boat with a paid slip for 4k. So I think I'm still doing ok. It does need a new top though. I just want to avoid this happening again. The mechanic said at full throttle rpms should hit 4200ish. Last time out I ran tilt full down and played with trim tabs and best case was 3700rpm but about 28mph. Thanks for any advice in advance.

[CptCrunchie]

Welcome to BOC!

It would be helpful to know what engine you have. Best to put that info in your signature square so we don't have to keep asking you when you have a question. Just click on your name, then 'edit'. Follow the tabs.

This is what I do.

http://www.baylinerownersclub.org/index.php/forum/technical-discussion/82493-1988-2556-5-7-cobra-omc-stern-drive-trim-the-boat-while-underway-ok#816043

Not surprised you could only get your RPMs to 3700; with your OD down all the way, you are bringing your bow down, which creates more drag.

I used to have a 15.25x15 prop on my 2459, so it could be close to what you should have, but following the link will show you exactly what your boat needs and where it rides best.

[JimMc]

In short your having the drive all the way down and using or not using trim tabs had nothing to do with the hub and coupler failure.

I could be wrong but I think in most cases that has more to do with the engine alignment to the Outdrive. So this was likely imminent regardless of who or how the boat was operated.

[6549vincent]

The guy I got the boat from said it looked like I hit something as the skeg was bent and there were some fresh nicks in the prop. Mechanic said wrong prop was on the boat which was the cause. I didn't ask what he took off just know what they put on I could find out tomorrow. I just want to avoid this again. Can too much throttle after no rise in rpm affect this?

[CptCrunchie]

"6549vincent" post=821819 wrote:
Can too much throttle after no rise in rpm affect this?

Not quite sure what you are asking. Affect what? Getting to WOT of 4200rpm, not using your tabs and trim properly, or getting it on plane at a lower rpm?

If you are to max RPMs and you still have more throttle you could give it, then yes, adding more is likely moot; you are literally wasting fuel. Just remember that WOT means wide open throttle, so the term means the throttle is all way open. However, it could be that your linkage is loose, or your engine needs work.

The only way I can think of for you to tell is if you added a fuel monitor to your GPC or chartplotter. That would tell you immediately what your fuel consumption is for the speed you are traveling, and it will also help you determine your best fuel economy for the various speeds and conditions.

As to the bent skeg and prop, you might want to have this addressed ASAP.

BTW, if it all works, $4K for a boat and slip is an amazing deal, even with the $2K added expense. Just remember, as hobbies go, this is one of the more expensive ones. For some, being on the water is a passion. For some, a pastime. For a few, a job. But for most, a well earned pleasure where the expense is relative. Might want to think about which on of these fits you best, and keep that in mind.

[builderdude]

If you were at full throttle (WOT) and couldn't hit 4200-4500 rpm you're likely over propped. As others have said: it had nothing to do with your coupler issue. Your coupler was likely on its way out do to poor engine alignment.

[Pcpete]

X2 with builder. Poor alignment and possibility lack of coupler grease.

If you hit something that would cause a problem the prop hub, that black grp sleeve, should be the point of failure.

As to the rpms, you may try to raise the drive a dash or two to see if the bow comes up and rpms increase. If you can't get into the right range, most prop shops have loaner props, expect to pay a deposit, for you to do some trial and error. It's a bit of a black art and Bayliners tend to be more accepting to prop changes than other brands.

[6549vincent]

How often should it be greased and is it difficult to do?

My next time out I'll try and raise the tilt up a bit and see where my rpms can get to.

[builderdude]

Zerk fittings are located at the aft end of the coupler, weather you can access them on your boat is another story. The drive shaft can be coated with grease upon re installing the drive as well.


Attached files

[6549vincent]

Finally had it out this weekend and I was able to get rpms up to 4000. I didn't leave it there. I usually run 3200 to 3500. How does this sound? I also used less fuel as well.

[Chief_Alen]

Your tach accurate ?

[builderdude]

So after the coupler replacement your back in the water Yes, verify your tach is accurate. Your WOT should be in the 4500 RPM range IMO

[6549vincent]

That was after trying to raise the outdrive up a little. About 3 bumps from all the way down. Afaik tech is accurate. I can put my timing light on it next time

[dktool]

"builderdude" post=821842 wrote:
[attachment]40349 wrote:
image.gif[/attachment]Zerk fittings are located at the aft end of the coupler, weather you can access them on your boat is another story. The drive shaft can be coated with grease upon re installing the drive as well.

This is a 1987 so....unless it was re-powered (leg wise) it is a Cobra which does not have a grease fitting on the coupler.

[builderdude]

Ah, "rubber hub coupler" I'm always assuming Mercruiser, my bad :S