How fast?

shilo

New Member
Jul 10, 2007
62
Ravenna, Ohio
Just wanting to know what I should expect as a top speed for a 1990 220 CC with a 260hp 5.7 merc with Alpha? The reason why I am asking is because I was out today with a GPS to check top speed and was surprised to find I was only running 36mph @ 4500rpm WOT. The prop is probably the original prop that came with the boat. Not sure if it is a Black Max, but it is an aluminum 3 blade 17 pitch in good shape. Sea Ray's prop chart calls for a 14.5"x 17. The boat is a large 22' ; 23'8" OAL with an 8'6" beam. The specs say it weighs 3500lbs, but I think it is heavier. I did notice that at 4000rpm I was running 30 or 32mph. It seemed like the last 500rpms really didn't add much speed and kind of sounded like the prop really wasn't grabbing the water well. WOT was only for 3 or 4 minutes max just to check performance. The trim tabs were full up and the outdrive was trimmed slightly up. I had expected to run 40 to 45mph. So, what should I expect out of this boat? Is 36mph about right as a max or is this the prop?
 
Hello, I have a 1991 225 BR with 5.7 ltr. My boat wieghs in at 3900# before 72 gallons gas and 8 gallons water and additional equipment. About the same boat as yours. When I first put it in for the year it ran 48 MPH on the speedometer, I do not have GPS. Now after being in the water for 4 months it runs around 40MPH . I believe your WOT RPM's is 4600.
 
Spun hub on the prop? Has the prop been reworked? I would think you'd be somewhere in the 40's with a 260hp engine and 3500lbs to push.
 
How can you tell
Spun hub on the prop? When I greesed the prop could I have put the prop on so as to "spun the hub?"

My boat is in the slip so I cannot pull it out of the water. Transmission blew on my suburban and will have to wait until November to borrow a truck and pull the boat.
 
I was thinking the same thing, that I should be around 42mph. I talked with Bret at BB Blades today. He said that I had 27% slip, which is kind-of what I felt running the boat. From 4000rpm to 4600rpm just didn't feel like it was pulling the way it should. Almost like not grabbing. I've been interested in trying the Revolution 4 SS prop from Merc and he said that would be an excellent choice for my boat. May only pick up a couple mph on top, but is really good for cruise and pulling. He said it should bring the slip down to the 15% range. He recommended trying a 14.6x 15, since I'm already running 4500-4600 WOT and the Rev 4 tend to run 200 -300rpm lower for a given pitch. They're sending out a test prop and I'll see where the WOT rpm's wind up. I think the original aluminum prop has fatigued and relaxed alittle. We'll see.
 

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