27 hydromotive and run it to 5400 RPM its ok ,,,,just not for hours and hours at that RPM !!

Well, if you are truely at only 3 LBS of boost at WOT(3 blades) at 4600, then what boost do you have at 5100(4 blades)? Need to know how much boost your making at WOT on both sets of props. Is there a boost gauge? Also, if you just bought this boat, check the timing at total advance to see where its set, very important. Im not sure where it should be on a 575 EFI, but lots of people on the board here will set you straight, dont want to burn any pistons!!! I run Labbed 28 Bravo 1 4 blades. Have done 81.2 MPH at 5300 RPM. They are a great "all around" prop. They say the 3 blade is faster at WOT, but IMO, the 4 blade is right there too. I would love to try your 3 blades on my boat if you decide to sell them. If you have them labbed, you may get 3 to 400 more RPM out of them. Talk to Brett at BBlades about the lab finishing, not Brad... you need to speak with Brett. But first get you boost #'s straight. If your at 3 LBS, a smaller pully may get you to where you want to be !!! :drink:

Thats interesting, I thought all 89s had the notch. Must have been an early 89

I would have Brett lab the 28s and live with it. Like you said..The mid-range is great.I ran mine at Erie alot and top speed was not everything in rough water

Birdog....you had a fast Bullet. What have you got for Top Gun speeds????

Listen to Birdog this is good advice. Labbing the 28's will give you more rpm which you need and you should gain 3 maybe 4 miles an hour. My guess is this boat with the motors in stock form should run high 70' maybe in perfect conditions 80. You have to remember the air quality this time of year sucks and it def. will result in a loss of hp. labb finish 4's it will get on plane faster better cruise and mid range, and handle better. The notch transom is probably good for a 1-2 mph.

Judging by his MPH and RPM #s, he will be alot faster with the 3 blades if he can get the RPMs up to 5000. Like maybe 80+ MPH with the 3 blades just lab finishing them! So, I say lab both sets and use the 3 blades for race days, and the 4 blades for family days....best of both worlds.

I truly dont no the boost i dont have boost gauges on the boat. I didnt think boost would change with different props. If the stock boost is 3 pounds shouldnt it be 3 pounds at the max rpm of the motor ?

I talked to tom at hydromotive. He recommended 27p 5 blade props for the best wot rpm with the most efficient cruising rpm. He also thought there 4 blade 28p would work good to. He thought i could pull a few more rpms with theres and a few more mph. Do you guys think i should try a set of them or just get my 29p labbed ?

I would try the labbing the 28 but i dont own them :). I borrowed them from a naughbor to try them. Read my newest post i put and let me know what u think. thanks

Well I have had great luck with the Bravo 1 props I bought from BBlabes. Talk to Brett the owner of BBlades and he can pretty much tell you how fast he can make your boat go...right over the phone! Hes the man when it comes to props. Ive new used Hydros, so I cant advise you on them. You need to know what RPM your engines make peak power at. 5200 sounds about right. Boost will increase with RPM. So for example, with the 3 blades at 4600, you may only be making 2 lbs of boost at WOT. With the 4 blades at 5100, you may be making 3 lbs of boost. But to set the boat up properly, you need to know how much boost your actually making and at what RPM the engines make peak power. 3 LBS of boost is conservative and you could be robbing yourself of some speed!....