Identifying my engine.

[jonathwill]

I have a 1988 Celebrity (I think its an open bow)that I would like to find out how many hp it has and also which is the best prop to use for tubing, skiing etc.
On the pinstriping on the side it says sport. if this helps
On the breather that sits on top of the motor has this info
mercruiser alpha one
4.3 litre
drive unit 0c412565
transom assembly 0c421062
also thunderbolt ignition

I know you guys will know exactly what I have!

and any personal opinions on the prop situation is welcome. I would like more speed out of it. seems to be pretty slow to me but this is my first boat.

and while I have your attention where could I find a Bimimi top for it. at this point it still has the original top and will need to be replaced next season for sure.

I appreciate your help and attention!

 

[HT32BSX115]

Re: Identifying my engine.

I have a 1988 Celebrity (I think its an open bow)that I would like to find out how many hp it has and also which is the best prop to use for tubing, skiing etc.
On the pinstriping on the side it says sport. if this helps
On the breather that sits on top of the motor has this info
mercruiser alpha one
4.3 litre
drive unit 0c412565
transom assembly 0c421062
also thunderbolt ignition

I know you guys will know exactly what I have!

and any personal opinions on the prop situation is welcome. I would like more speed out of it. seems to be pretty slow to me but this is my first boat.

and while I have your attention where could I find a Bimimi top for it. at this point it still has the original top and will need to be replaced next season for sure.

I appreciate your help and attention!

Howdy,


Welcome Aboard!



Well, you're in the wrong forum probably. You're asking about Props. (there is a prop forum)


A Mod will move this thread as we speak!

Before you ask the above questions however, (and we provide meaningful answers) you need to know some things about your boat.


Take it out and run it at WOT (Wide Open Throttle) on the lake with full fuel and 3 or 4 people in the boat.

If one of the people has a smart phone (with GPS) or you have a GPS, note the actual sustained speed and RPM, then report back and ask your question and provide that info!

That is the way to determine if you actually have the correct prop installed. (assuming you have the right drive for your engine.......and, If it's "stock" then you probably do)

In general, your boat should reach maximum RPM (according to your owners manual) at WOT with the correct prop installed. I do not know (off the top of my head) what the WOT range for a 4.3L engine is but it's around 4400-4800RPM OR SO.

Someone will jump right in here with the correct numbers.

Regards,


Rick

 

[achris]

Re: Identifying my engine.

mercruiser alpha one
4.3 litre
drive unit 0c412565
transom assembly 0c421062
also thunderbolt ignition

I know you guys will know exactly what I have!

and any personal opinions on the prop situation is welcome. I would like more speed out of it. seems to be pretty slow to me but this is my first boat.

I can tell you all you need to know about the drive, but without the ENGINE SERIAL NUMBER all I can tell you about it is that it's most likely a 4.3, because you told me.... ...

As for the prop, we need current prop pitch, current top speed (in knots please), current WOT revs, and drive ratio (which SHOULD be 1.84:1 if it hasn't been messed with).

Chris...........

 

[Fun Times]

Re: Identifying my engine.

ENG: 0C318951 Model #443S100AS MERCRUISER W/ PS 4.3L ALPHA 175 H.P (1988)
DRV: 0C412565 Model #5010184AS MERCRUISER ALPHA R.H. ROTATION 1.84:1 (1988)
Hull Id: CYG*****D888 Boat Length: 019
Manufacturer: CELEBRITY Width: 008
Nbr of Motors: SINGLE Hull Material: OTHER
Merc service manual part number 90-12410 - ENGINES - GM V6 SERVICE MANUAL (1983-1993)
Merc parts catalog part number for the engine is 90-17468 - 175 HP/ 4.3L/205 HP/4.3L/LX
Max. RPM (at W.O.T.) 4400 - 4800 RPM

 

[achris]

Re: Identifying my engine.

[size=+1]ENG: 0C318951 [/size] Model #443S100AS MERCRUISER W/ PS 4.3L ALPHA 175 H.P (1988)
DRV: 0C412565 Model #5010184AS MERCRUISER ALPHA R.H. ROTATION 1.84:1 (1988)
Hull Id: CYG*****D888 Boat Length: 019
Manufacturer: CELEBRITY Width: 008
Nbr of Motors: SINGLE Hull Material: OTHER
Merc service manual part number 90-12410 - ENGINES - GM V6 SERVICE MANUAL (1983-1993)
Merc parts catalog part number for the engine is 90-17468 - 175 HP/ 4.3L/205 HP/4.3L/LX
Max. RPM (at W.O.T.) 4400 - 4800 RPM

Ok... where did you see that? I hunted that post up, down, left and right.... I DID NOT see an engine serial number there!

 

[Fun Times]

Re: Identifying my engine.

Ok... where did you see that? I hunted that post up, down, left and right.... I DID NOT see an engine serial number there!

Sometimes when you run the drive or T/A the engine comes up.

 

[jonathwill]

Re: Identifying my engine.

Ok just got out of the water.
Prop size is 14.5 x 20
At rpms from 4400-4800 was 22-25ish knots.
I have plenty of throttle left.
My prop is 3 blade ss
I have an extra aluminum 4 blade 14 x 20

Ok guys do your thing get me in the straight and narrow.
Thanks

 

[Maclin]

Re: Identifying my engine.

Those numbers do not compute. The drive ratio should be and is probably actually 1.8, and using that I get 40% slip, so something is not accurate and I suspect the RPM is not. With normal slip of 15% I get a drive ratio of 2.58.

I would verify the actual RPM's with a separate tach. I am suspecting the tach is set for an 8 cylinder instead of a 6 cylinder, and that the 4800 rpm is more like 3500 rpm in actuality.

The actual RPM's must be verified before any solid advice can be given.

 

[jonathwill]

Re: Identifying my engine.

I just spoke to a local boat shop that pretty much said the same thing. any recommendations as to how to do the tach test? Do I buy a small tach and attach it to my existing tach wires? or Rewire with the new tach?
Now the dumb question where do the tach wire attach to the motor at?

What should the speed be with the present set up? ball park estimate is fine.

I am sure of the speed I used my Phone GPS it did correspond with the boat speedometer.

thanks guys

 

[jonathwill]

Re: Identifying my engine.

Ok after taking the existing tach out and looking it over. There are no settings on back of tach but the adjacent wall underneath dash there is a black cover with a plug in. it has settings a, b, c, d, e what setting should it be set too. Im thinking this could be the prob. I unplugged the plug and the tach didnt record any rpms at all. any ideas

 

[Maclin]

Re: Identifying my engine.

What brand is the tachometer? Sometimes a google type search on that with "boat tachometer" can wrangle up a manual or at least good info from blogs.

Dwell meters usually have a tach function, works by getting a signal from a spark plug wire, like a timing gun. Also you could ask a shop or local parts counter if they have a portable "shop tach" you could use.

 

[jonathwill]

Re: Identifying my engine.

Update. Ok I bought a tach, wired it in and found my prob. I was actually well below 4400-4800 rpm. It was off around 1300-1500 rpm. Correctly adjusted the settings in the existing tachometer I got 35ish mph and could only get right around 4100 rpms. Im gonna pull off the 3 blade ss 14.5x20 and put on the 14x20 4 blade aluminum.
The settings for the tach were located on a black plastic cover on the adjacent wall under the dash. Thats a weird place to have that I think.
Is it better to operate at a slower speed at the correct rpms?
Or is it better to have more speed and less rpms?

And much appreciation for all the info guys. We had a wonderful time the last few days on the water. Now if I could only not wipe out so hard trying to do the 360 on the kneeboard.

 

[QC]

Re: Identifying my engine.

It's better to have her propped for a typical load and landing right in the middle or toward the top of the RPM range with her trimmed out and all she's got. Going from the 3 Blade SS to a 4 blade Aluminum of the same pitch may net no RPM gain, but won't know until you try of course. Do a little more reading of different prop threads here and you'll get a little bit of a handle on this.