1999 215EC top speed question

John Boudreau

John Boudreau

New Member
Aug 3, 2021
14
Boat Info
1999 Sea Ray 215EC
Engines
Mercruiser 5.0 Litre, Alpha 1 Gen 2 outdrive
I purchased this boat from a close friend last summer, it only had 93 original hours on the motor. Original manifolds and risers, rebuilt carb. The engine is a 5.0 Thunderbolt ignition ( 220 HP ), Alpha 1 Gen 2 outdrive. Currently it has 171 hrs. I have no issues with this boat, it runs like a clock. I put a 4 blade prop Alum prop on it this year to help with my hole shot ( which it did ), next year adding trim tabs. My question is : I read all these posts of guys getting 40-50 MPH top speed with this boat, I don't even come close to that, With two people and a half a tank of fuel, I get 27 MPH on GPS @ 3800 RPM, WOT maybe 33, only if it is flat calm. Is this normal or do you think something is going on ?
 
What RPM are you spinning at WOT?

that could be a clue as to whether you’re getting all available power.

At least that seems to be the theme I’ve noticed.

Have you checked the chart for your model in the SeaRay archives?
 
I can get the RPM up to 4800-5000, and no I haven't checked that, thanks for the response.
 
If you get 4,800rpm and only 33mph at WOT something is wrong. Dirty hull, wrong prop, outdrive not trimmed properly. How did it run before you changed props, what did you take off and what did you replace it with?
 
it had a 14-1/2 X 19 prop on before, and now I have the same only a four blade. It went about the same at top end just a little quicker to plane out with 4 blade. I trim it properly, boat is on a mooring in salt water, always has a little growth on bottom, didn't think it would make that much difference
 
John Boudreau said:
it had a 14-1/2 X 19 prop on before, and now I have the same only a four blade. It went about the same at top end just a little quicker to plane out with 4 blade. I trim it properly, boat is on a mooring in salt water, always has a little growth on bottom, didn't think it would make that much difference
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Someone that knows more than me will chime in….but I think when you add blades you’re supposed to drop size…
 
John Boudreau said:
it had a 14-1/2 X 19 prop on before, and now I have the same only a four blade. It went about the same at top end just a little quicker to plane out with 4 blade. I trim it properly, boat is on a mooring in salt water, always has a little growth on bottom, didn't think it would make that much difference
Click to expand...
This long distance keyboard trouble shooting is often a bitch. Going by what info you provided so far, you're in the correct WOT range with 4,800rpm, the prop is correct size.....but what's 'a little growth', got any pics....I'd say pull the boat, clean the hull.
 
A little growth can have a VERY dramatic effect. That is the first step - pull it out and clean it PERFECT. Only then can you start diagnosing other things... although it's quite possible this is the whole problem. Yes, you should easily be able to get into the 40MPH range (see my sig).
 
The growth I am speaking about is some green on outdrive and a thin film of green on hull, no barnacles or anything protruding
 
If your certain about the slime on the hull maybe a slipping prop hub if it was a used purchace
 
5.0 220 HP Alpha Gen II would not achieve 50 mph ever. So put the original prop back on and record your numbers then post back. Guys posting 48-50 mph probably have 5.7 300 HP with Bravo III's and even then I doubt it.
 
Correct - I have a 5.0mpi and I’m lucky to hit 45mph, alone, unloaded, tucked, trimmed with the wind at my back. At full throttle I’m just wasting fuel anyway.
 
If it makes you feel any better I grew up with a 79 Galaxy BR with a VP 120 hp I/O.

one time on the way to PIB my dad and I hit 22mph coming down the wake of a big motor yacht.

Typically wot equated to 19 mph. And I thought we were flying!
 
thanks for your replies, I kinda figured those numbers were slightly inflated. I think if I went out alone with 1/4 tank of fuel and no gear with optimal sea conditions I may hit 38-40MPH.
 
John Boudreau said:
thanks for your replies, I kinda figured those numbers were slightly inflated. I think if I went out alone with 1/4 tank of fuel and no gear with optimal sea conditions I may hit 38-40MPH.
Click to expand...
No, as I mentioned above, you should get into the 40's.
 
is that a Carberated engine or MPI?
 
About the bottom growth, I got the same numbers when I first put it in for the season with new ablative bottom paint, so I don't think it is that. I have heard that 4 blade props hurt your top end speed, any truth to that?
 
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