What went wrong?

[Andrew1]

Hi guys,
I need some help and advice with my prop problem. The boat is 1998 Bayliner Ciera with a 5L Merc and Alpha 1 drive. I bought it two years ago with a 14 ½ x 17 three blade aluminum prop. It has been working OK, but my WOT is just above 4000 rpm and I have been having problems getting on plane with more then four people. I thought that going to a 14 ½ x 15 would give me an additional 400 rpm at WOT and make it easier to plane, but I was in for a big surprise. The boat would run OK on low rpm, but the prop would spin every time I tried to increase the speed. What went wrong? Did I reduce the pitch too much or is it the OD rather than the pitch problem? Any other possibilities that I am not aware of?
Thanks,
Andrew
P.S.
Anybody interested in a brand new, original, 14 ½ x 15 Mercruiser Vengeance SS prop?

 

[xtraham]

Re: What went wrong?

did you buy the replacement prop new ?
if it was used the hub may be slipping.........

 

[tommays]

Re: What went wrong?

We need a littel more info on the boat a healthy 5.0 should be able to spin a 17 in prop on most boats


Tommays

 

[Andrew1]

Re: What went wrong?

Sorry guys,
I thought I included the full boat info, but I guess I did not. It is a 2355 (23 1/2 ft) Bayliner Ciera. The prop I tried was a brand new three-blade SS 14 1/2 x 15 and there was no sign of hub slipping.
Thanks,
Andrew

 

[Crownie2]

Re: What went wrong?

Can you tell us a little more about the "prop spinning" problem? This should not happen if the other, original prop didn't do it...

I'd say your thinking on the 15" prop was OK and the Vengence should work.

Bob

 

[Andrew1]

Re: What went wrong?

Here are some more details of what happened. On low rpm and low speed, everything seemed OK. When I increased rpm and tried to get to plane the boat would initially gain some speed, but then rpm would go to the roof and the boat would slow down. I tried to get to plane few more times with exactly same result. There was only me on the boat and no extra load so the weight was not an issue. Excuse my terminology, but it seemed like the prop lost its traction and was just spinning in the water. After taking the prop off, I carefully examined the plastic hub and there was no sign of it slipping or any other damage.
Thanks,
Andrew

 

[tommays]

Re: What went wrong?

i think your dealing with a boat thats underpowered and most likely needs a lot of RPM just to keep on plane once it gets there

I would think the 15" prop is blowing just before the boat can get on plane when the load is the highest

A 15in prop with a 5.0 is allmost like a test wheel you would probably be able to get it spinup tied to the dock

You can contact bayliner they are very good about finding out the orginal specs

BUT it should be able to use the 17 in prop if the motor has been tuned up correctly and is in good condition and the bottom is clean


Tommays

 

[walleyehed]

Re: What went wrong?

It's still possible to have a spun hub if it's a std hub...
If it's a flo-torq II we have other issues.
Make sure your drive is all the way down when taking off.
I've seen a couple of cases where hydr. lock would not let the T-N-T cylinders go clear down (retracted).

 

[Andrew1]

Re: What went wrong?

It is a flo-torq hub.
Andrew

 

[walleyehed]

Re: What went wrong?

I would make darn sure the drive "IS" going all the way down...if it is, do we have anything mounted to the transom with-in 12-14" of center line?
The Vengeance is also just an entry-level SS prop...it "may not" have enough cup to handle the load.
Any way you could get your hands on something like a Mirage, or any other known prop?

 

[walleyehed]

Re: What went wrong?

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