1990, 225 Sundowner 5.8L, 32mph??? is this right?

[fireicyhott]

I originally posted this in the Four Winns forum but it got no responses. This forum is the one that helped me and this is somewhat motor related. Thanks,




Hi all,

I have recently gotten a 1990 225 Sundowner cuddy with a 5.8L OMC/Cobra drive with Holley 4bbl carb and points.

Been doing some work on the boat and it only has 290 hours on it.

Right now with 15x17 prop it will do 32mph at WOT which seems to be about 4100-4400 rpm.

My uncle who use to own boat said he THOUGHT he remembered it doing 42mph. I don't think so.

Is 32 mph about right for this boat with this motor????? Anyone else have this combination?

Thanks,

Jeff

 

[Haut Medoc]

Re: 1990, 225 Sundowner 5.8L, 32mph??? is this right?

I don't know enough about OMC or your boats configuaraton, but.....
I think it should be faster.......
I can get 37 mph (GPS) with my 188 HP 302 ford on my '73 Sea ray.....
That's with a 14x17 stainless......​

 

[fireicyhott]

Re: 1990, 225 Sundowner 5.8L, 32mph??? is this right?

Hmmmmm, my 32mph is based on regular speedometer (not GPS) which may or may not be accurate.

Also bottom could use a paint as the bottom paint is wearing off and previous owner had left it in water.

Would love to hear from others. Motor now runs great, carb is opening all the way. I am just wondering if I can get any more out of it without changing prop. I don't want to lose holeshot to gain more top end. If 32mph is it then I guess I will be happy with that.

Any thoughts?

Thanks,

Jeff

 

[fireicyhott]

Re: 1990, 225 Sundowner 5.8L, 32mph??? is this right?

Hey Haut,

Is your Sea Ray a cuddy cabin? Mine is and it weighs 3800lbs!!

 

[MikDee]

Re: 1990, 225 Sundowner 5.8L, 32mph??? is this right?

I originally posted this in the Four Winns forum but it got no responses. This forum is the one that helped me and this is somewhat motor related. Thanks,




Hi all,

I have recently gotten a 1990 225 Sundowner cuddy with a 5.8L OMC/Cobra drive with Holley 4bbl carb and points.

Been doing some work on the boat and it only has 290 hours on it.

Right now with 15x17 prop it will do 32mph at WOT which seems to be about 4100-4400 rpm.

My uncle who use to own boat said he THOUGHT he remembered it doing 42mph. I don't think so.

Is 32 mph about right for this boat with this motor????? Anyone else have this combination?

Thanks,

Jeff

42mph should be about right, plus your prop, & rpm's seem about right though? are you sure your props not slipping on the rubber hub? or, (heaven forbid) your coupling is slipping. I've had both of these things happen to me on seperate boats, and I know how they affect the running.

The other posters here are pretty much right on with their speed, And I had a 79'- 24' SeaRay Cuddy with a 350/260hp (5.7 Chevy) Mercruiser that would 40mph, fully trimmed out, but I had thru-hull exhausts with mufflers, and ran it on synthetic blend oil, also running a 14.5X17" merc. alum. prop. That was also a heavier boat then yours.

 

[Haut Medoc]

Re: 1990, 225 Sundowner 5.8L, 32mph??? is this right?

Hey Haut,

Is your Sea Ray a cuddy cabin? Mine is and it weighs 3800lbs!!

Its an SRV, so yeah, basically a cuddy......
I don't know what it weighs, but it ain't light & has a 75 gallon tank...

 

[fireicyhott]

Re: 1990, 225 Sundowner 5.8L, 32mph??? is this right?

Haut,

How do I know if the prop is slipping on the rubber hub? I do have a stainless prop of the same pitch 15x17, might try that one but not sure if that is going to help on top end.

Thanks,

Jeff

 

[Haut Medoc]

Re: 1990, 225 Sundowner 5.8L, 32mph??? is this right?

Haut,

How do I know if the prop is slipping on the rubber hub? I do have a stainless prop of the same pitch 15x17, might try that one but not sure if that is going to help on top end.

Thanks,

Jeff

Make an index mark on the top of the prop nut & a corresponding on the inside of the prop with nail polish or a magic marker.....
Run the engine normally in the wter in gear....
If the marks stay lined up, it is not the hub.....
If they do not, it is the hub.....

 

[Boomyal]

Re: 1990, 225 Sundowner 5.8L, 32mph??? is this right?

....I can get 37 mph (GPS) with my 188 HP 302 ford on my '73 Sea ray.....
That's with a 14x17 stainless......​

....and how long is your boat?
Haven't you thrown that new 351w in yet?

 

[Haut Medoc]

Re: 1990, 225 Sundowner 5.8L, 32mph??? is this right?

....and how long is your boat?
Haven't you thrown that new 351w in yet?

22 footer.....
No, not yet....
That's a winter project.....

 

[fireicyhott]

Re: 1990, 225 Sundowner 5.8L, 32mph??? is this right?

Haut,

If the marks do move and therefore it is the hub, how hard is that to fix?

Do you think the stainless steel prop will help at all since it won't flex as much?

Jeff

 

[coastalcruiser]

Re: 1990, 225 Sundowner 5.8L, 32mph??? is this right?

Is the bottom clean?
Because it should be, that can make you go slow.

Also bottom could use a paint as the bottom paint is wearing off and previous owner had left it in water.

 

[Don S]

Re: 1990, 225 Sundowner 5.8L, 32mph??? is this right?

If your prop actually slipped, it would keep slipping and get real bad, real fast. To the point that anything over idle would make it slip (Within seconds or minutes, not days).
A slipping prop is not your problem.
Rough bottoms from some paint, bare spots, rough spots, etc. all make the boat slower. Plus the speedo may be partially plugged and preventing a true reading.
Get (Beg or borrow a hand held) and check your speed on the water. Then verify the tach with a good shop tach, have you tried using the trim?????

 

[MikDee]

Re: 1990, 225 Sundowner 5.8L, 32mph??? is this right?

If your prop actually slipped, it would keep slipping and get real bad, real fast. To the point that anything over idle would make it slip (Within seconds or minutes, not days).
A slipping prop is not your problem.
Rough bottoms from some paint, bare spots, rough spots, etc. all make the boat slower. Plus the speedo may be partially plugged and preventing a true reading.
Get (Beg or borrow a hand held) and check your speed on the water. Then verify the tach with a good shop tach, have you tried using the trim?????

Maybe so Don, but a slipping coupling can act like a clutch beginning to slip on a car, you'd get most of your speed, but not all, under building resistance. I've been there, had that happen to me on an 18.5' Wellcraft airslot with a 165hp straight 6 Mercruiser. Granted if his speedo is off, that is the problem, but I think you'd know if you were doing 42mph, as opposed to 32mph.

 

[Don S]

Re: 1990, 225 Sundowner 5.8L, 32mph??? is this right?

but a slipping coupling can act like a clutch beginning to slip on a car, you'd get most of your speed, but not all, under building resistance.

Bull hockey. If a coupler slipped, it would slip just like a prop. Only thing is if it started slipping, you would smell the burned rubber , see the smoke, loose rpm till you slowed down.

 

[MikDee]

Re: 1990, 225 Sundowner 5.8L, 32mph??? is this right?

Bull hockey. If a coupler slipped, it would slip just like a prop. Only thing is if it started slipping, you would smell the burned rubber , see the smoke, loose rpm till you slowed down.

Sorry Don, I totally disagree! After I rebuilt the 165hp/250 Chevy straight 6, that would then turn 5k rpm with a 19"pitch prop, and do 45 easily, the problems began, because I didn't replace the original coupling which appeared fine. With 2 people in the boat, it was fine, then when I added 2-3 friends, or relatives, and with semi rough seas, I would struggle to get on plane, I was lucky to get it to plane, or hold it's speed, even though the engine was strong, I could see my tach rising fine, and going to max rpm when required, although not making much headway! at later dates, without the extra load, the boat appeared fine for awhile, then gradually got worse, in windy rough seawater, under the doghouse, who can smell rubber burning, or see smoke? I'd say mine wasn't slipping that bad, at least not in the beginning.

 

[Haut Medoc]

Re: 1990, 225 Sundowner 5.8L, 32mph??? is this right?

Bull hockey. If a coupler slipped, it would slip just like a prop. Only thing is if it started slipping, you would smell the burned rubber , see the smoke, loose rpm till you slowed down.

Crap, now Don S looks & sounds like Col. Sherman Potter, in my mind's eye!....

 

[whywhyzed]

Re: 1990, 225 Sundowner 5.8L, 32mph??? is this right?

Use GPS- pitot-tube speedometers are not very accurate

 

[QC]

Re: 1990, 225 Sundowner 5.8L, 32mph??? is this right?

I'm with kjdkjd. We need accurate information to discuss this.

Fire and ice dude,

I believe 32 MPH is probably slow. I get a calculated 40.8 MPH with a 17 inch pitch, 4200 RPM, a 1.41 Gear ratio and 15% slip; 33% slip with your numbers . . . All of this is kinda screwy without a GPS and a precise WOT RPM. The bottom needs to be cleaned up for sure to get the slip down. 15% is reasonable, but it could be even better or worse depending on quite a few variables. Also need to insure the prop is clean, good, right etc. There have been a lot of these speed threads that start heading down prop hub and coupler deals before we even have accurate numbers. Don't start swapping anything out until the info is correct first . . . will potentially save you a ton of money

 

[happycamper]

Re: 1990, 225 Sundowner 5.8L, 32mph??? is this right?

fireicyhot,
What is the gear ratio in your drive? I'm surprised to hear you're using a 15x17 prop with a 5.8L.

I propped down to a 15x17 on my little 3.0L for altitude, and I get 37mph at 4300prm (speed measured with a GPS, which agreed with speedo).