Spinletto

iTrader: (1)

I've got a 06 fever with a 496HO in it with a bravo 1 outdrive with 1.5 gear ratio and I currently have a bravo 1 28 pitch prop. At full throttle I've got an RPM of 4900 and I'm only getting 61mph. Fountain says with this engine I should be getting around 70. I'm assuming I've got the wrong size prop because with these numbers according to the calulator on Mercury Racing's website I'm getting around 30% slip. Does anyone know what pitch prop Fountain puts on the 29's with a 496 HO?

rgrgoog

iTrader: (3)

That seems to be an awefully high pitch prop for just a 496HO. I would think you would be running a 24P or 26P B1. Here is what I would do. I would check the outdrive to be sure what gear set you are running. I would go out and get a GPS and another Tach (besides the one in your boat) to see what your actual RPMs and GPS speed are. You could have a faulty tach. If you bought the boat used the previous owner could have "beefed" up the engine too. You should be running more speed than that given your prop and rpms. You either have alot of slippage or your tach/speedo could be off. I would eliminate/verify my readings first.

For example I run 30P B1s at 5200 and 32P B1s at 5000 and I have 600hp/engine. I usually get around 86-88 GPS depending on how much fuel/load/people. etc. I can run 86 any day any load though. That equates to about 13% slip. You should be somewhere close to 13 I would think.

Spinletto

iTrader: (1)

I was getting my speed from the GPS. As far as the engine tach isn't 4900 about normal for a 496 HO at full throttle?

rgrgoog

iTrader: (3)

Yes that would be normal. I was suggesting you check your tach to see if it is in fact accurate and that you are truly running 4900. If the prop is not damaged, I would begin to think it would seem that something is slipping somewhere in your drive system. You may be running the engine at 4900 but the prop is not spinning what it should be. You should be seeing higher speeds IMO. I am by no means an expert so I would wait to see what some of the more experienced guys on here say.

mapism

It's ok, but just for your reference, on my 27 with a stock 496 HO and B1 26" prop I can see exactly 70mph at 5050/5100.
With the 24" prop, I hit the limiter (at 5150/5200).
Your numbers don't stack up, you must have either a much shorter prop or a different ratio...

Racerngr1

I would try a 24 Hydromotive or a 26 B1 and see how those work. I am below 10% prop slip with my combo right now after a bit of back and forth work with the prop company.

bob_t

Fountain typically puts 1.65:1 ratio gears with the 496 packages. The later 27 Fevers left Fountain with 496HO's, 1.65:1 B1X drives and mostly 28P B1 props. The ran ~ 68 - 70 mph with one person and low on fuel. With a couple of people and 65 gallons of fuel, they were slower than that. Someone must have changed your outdrive if you have a 1.5:1 ratio, especially in a 29 Fever with a 496 HO. Just for reference, with a 1.5:1 ratio, a 2006 29 Fever with a "strong" 525 EFI only spins a 28p B1 prop. Most later 29's with 525 EFI's work really well with a 26p B1 prop, for average boating (ie, more than one person and "adequate" fuel in the tank). Sounds like you have the wrong prop/outdrive for a 496 package if it is a 1.5:1 ratio outdrive. Was this a 525 boat that someone took the engine out an put a 496 in it before they sold it? I would bet that 61 mph is about the right speed for a 5850 dry weight boat (the 2006 single engine 29 Fever), especially if you have much fuel in that 112 gallon tank (another ~ 700 lbs), on a nice warm day with 496 HO trying to spin a 28P B1 prop with a 1.50:1 drive. The older - "pre windshield", single engine 29s' were lighter weight (~ 5500 lb) and with a 500 EFI only ran ~ 72ish with 1.5 ratio outdrive and 24p or 25p hydromotive Q-IV props. A late model 27 Fever with a 496 HO is an upper 60's mph boat so I wouldn't expect that a 600 lb heavier 29 (dry weight) would run faster, even with the same people/fuel load.

flying J

I agree...A 496HO spining a 28pitch with 1.50 gears aint gonna happen! Now with 1.65 gears all day long and a labbed 30 will work if you still have high slip numbers. Double check everything especially the tach and the gears ratio

mapism

Fwiw, my 27 Fever surely is one of the latest 27s (HIN ...E607), but left the factory with a different setup: 496HO, 1.5 B1XR and 24p B1 prop (l/h), 19" X-dim.
66mph at 5150 on performance report, but now (with CMI exhaust and a labbed 26p B1 prop), she reaches 70mph with very light load.

Btw, does anyone know which is the most recent HIN for a 27? I suspect that they didn't build many others after May '06.

breakitout

You probably do have one of the last 27's out of the factory.. good looking boat too!