2255 ciera Prop size-gctid392215

[Guest]

Hi I have a 1991 2255 ciera powered by a merc 4.3lx (i think 180hp) with alpha gen 2 sterndrive. The current prop which was on the boat when I bought it is a 4 blade stainless steel which I have been told is either 15 x 21 or 17 x 21 which I think is too big as I can't get revs above 3200rpm and speed is around 15knots ,Engine timing etc has been checked and has been serviced. Anyone know correct size for this boat? (There is additional weight of a transom mounted kicker motor)

[Guest]

Im running a 3 blade 15p at 7000ft at 36mph or so. I found a site that may help you

http://www.dansdiscountprops.com/propeller101.htm

[Guest]

Hi Thanks for the link helped a lot.

[andymuz]

3 blade 16x16 what a diffrence

[Guest]

Cheers just got a loan of a 16 x 16 to try ,just waiting for some decent weather to put on and try.

[Guest]

I used to own one of those: '91 2255 with the 4.3.

Can't remember the prop specs, but remember that we had a 3 blade "elephant ear" design with wide blades. It worked terrific. She would pop up on plane with 4-5 adults no problem. Top speed in the low 30 mph range. Seemed like an underpowered package for a 22 ft. hull but she worked surprisingly well once properly propped.

[Guest]

Just an update changed from16x16 prop to a 151/4x15 as 16x16 had some damage.

Revs now upto 4500rpm but still only get 10-12mph gets to speed quicker now. sea state was was approx half metre swells. Would the weight of kicker on transom(out of water) and the fact that boat has camping type cover on effect speed?

Just to add half tank of fuel 2 people on board engine timing filters etc all checked, Extras internal are a microwave and approx 2 cases of refreshments!!

thanks in advance David

[itsabowtime2]

RPM's is much better, but your speed, is that with a GPS or the factory speedo? If speedo, bring a GPS on board and see what you get. At those speeds you are not even getting up on plane.

Was the boat on plane? If so the speedometer is off. Very common problem.

Your load was very typical. The top will slow you down a bit if it was up and the kicker may add a few seconds to get up on step but neither should cause you not to even achieve planning speeds unless something else is wrong.

[Guest]

hi it is gps speed ,ther is a small amount of algea growth on leg if that would make a difference.

[Guest]

These numbers just don't add up. You sure the hub isn't broken on the prop? A 15" prop with a 1.8 gear ratio (typical) would move you at 32-34 MPH.

[itsabowtime2]

Growth on the hull would, but for your numbers that would be a lot of growth. This different prop, is it new? If not as Carlos said it could have a spun hub. You should be hitting 30mph, give or take. Something is not right.

[Guest]

The prop is a loaner from a fellow boater who keeps it as a spare(, I have a new one on order so will post when it arrives hopefully by next weekend.

I am new to boating so would trim and tabs effect the speed this much , Engine was trimmed all the way down tabs I trimmed all the way down then back up a touch.Thank you for replies .

[Guest]

Hi, Late Riser!

I┬┤ve just bought a 2255 myself for this season and I have similar problems to the one┬┤s you have. The differences that I have is that my boats speed is a bit higher. I also got the merc 4,3 L of 175hp but with a Alpha One Gen 1 stern drive.

With my original alu prop (that came along with the boat) I have this result:

3 blade 15x17p, speed is 27 knots (31 MPH) rev 4000rpm, boat plans out very slow (with normal load 2 adults, 2 kids and additional packing, 50l water and gas)

With a Phirania (composite prop of two different models) i got the following result:

4 blade 15x14p, speed 21 knots rev 4400, boat plans out very fast

3 blade 15x15p, speed 23 knots rev 4400, boat plans out fast

From what I can read on different sites, this tread and after talking to a mechanic, this boat, with this engine should run at a speed over 30 knots with a normal load. It doesn┬┤t!

One of all mechanics that I talked to, told me to look up witch gear ratio I have on my stern drive (I don┬┤t know witch gear ratio it should have thou) because the drive might have been changed over the years and a stern drive with a faulty gear ratio might have been installed. This I have to look up when i pick my boat up after the summer season has ended. He also recommended me to do a compression test on each cylinder to check that the engine is running well.

Does any one know witch gear ratio the original stern drive (Alpha One gen1) with a 4,3L should have?

Late Riser, have you the right gear ratio on your drive? And is your drive the original drive for that drivetrain of the model year of -91?

Does any one have any suggestion what to next?

[Guest]

Hi again!

I read your latest post again and, Yes, the trim and tabs might affect your speed a lot. I┬┤m also new to boats this big and in the beginning of the summer I played with the trim tabs when I was moored, and when I was going home I first couldn┬┤t get the boat to plan because I trimed down the tabs all the way to the bottom this resulted in a max speed about 13knots with the bow pointing the stars. Once I trimed the tabs up completely I┬┤t worked just fine again.

//Mike

[Guest]

Hi acedarkman

drive is original with 1.81 (i think of the top of my head) ratio, not sure on the alpha 1 gen 1 ratio. I have a new prop which is a mercury black max 15 x 15 which i will hopefully be trying out this coming weekend( British weather permitting!!) and will post my results on monday.