Re: Not getting the speed I should!
 

Double check your tach.20% slipage on a mirage plus seems high for your boat.I have a 257 mirage wich weighs 5000#s loaded up and has a 24 deg deadrise and I hit 69 mph at 5350 rpm with a 23 mirage plus prop.My slipage is 12%.I had a inacurate tach reading that progresivly got worse as rpm increased.At full throttle I was out 300 RPM.I don't think your slipage should be any worse than mine.What is the dead rise of that boat?I noticed with my boat that the slipage is lower with higher horsepower engines.

Re: Not getting the speed I should!
 

Not sure if this factors in to your prop calculations, but according to the manufacturer that model, empty, weighs 4400 lbs. A full 90 gal. fuel tank adds 751 lbs. Plus three people at 150...your total weight is closer to 5600 lbs.

???

D. Ocean
Pompano Beach, FLA

Re: Not getting the speed I should!
 

Just go buy a cat and be done with it :) Seriously though, if you added 120 pshp and added 200 lbs to the transom at the same time, a 9 mph gain is pretty decent.

Re: Not getting the speed I should!
 

That weight was with less than a 1/4 tank of gas and 2 people. There could be something wrong with the 23P prop I was trying I'm taking it back today. We checked the RPM's and it is a 100 off from what the tach say's and I'm taking that into consideration when posting RPM's.

With talking to other 252 owners in Texas and other places and reading alot the speed just seems low for that hull. Every one I've talked to that owns a 252 says they don't have the hook in there hull (but maybe they just don't know it?) And I'm wondering if that might be part of the problem. Going to call Throttle up to see if I can demo a prop.

Russ

Re: Not getting the speed I should!
 

Did you check your tach at idle or full throttle.I would say the props are pretty good because the slippage is about the same on 23 versus the 25.

Re: Not getting the speed I should!
 

Talked with Throttle Up and bought a Bravo 1 24P 4 blade. The tach was checked at idle, at 3000 and at 5000. But I might change it out just to check.
For some reason I'm just getting alot of slip with the 3 blades. Might just be the prop's I tried. But really can't try my freinds 23p and 25p props because they don't have solid hubs. And I blew out the brand new hub on the 23 I had.

Russ

Re: Not getting the speed I should!
 

Russ,if your friends are running merc props just buy 1 solid hub kit,you can knock the hub out in 2 seconds,substitute yours in and try it. I own 5 diff props but only 2 hub kits,it's a waste of money to buy a hub for each one (but all my current props are merc). You start getting into 500 hp and 24 pitch props you'll need solid hubs anyways.

Re: Not getting the speed I should!
 

I'm getting a solid hub kit with the prop from Throttle Up. I just hope the bravo 1 24P prop works better than the others I've tried. The boat just doesn't seem to get out of the water very well. I have the boat trimmed to to almost half way on the indicator and just don't feel the lift and don't even see a rooster tail trimmed that high.

Re: Not getting the speed I should!
 

Well I ran the prop today 24p Bravo 1. 97 degrees today very calm.
3000 rpm's was 36MPH
3500 rpm's was 43MPH
4000 rpm's was 50MPH
4800 rpm's was 61MPH
5000 rpm's was 63MPH
5200 rpm's was 66MPH
No diff than the Mach prop 24P

Pics are at WOT full trim. Does it look like I'm getting enough bow lift?

Does anyone have a clue on what I would need

Re: Not getting the speed I should!
 

just so you know, bravo 1's are actualy about 1.5 -2 deg pitch less then stamped when comp. to any other prop.