boatinbill

I took the '99 271 Fastech (w/Hp500EFI) out this last weekend for the first time this year. Over the winter I changed the spacer in the Bravo One trim from the Bravo Three position to the Bravo One position (thanks for the suggestion from this forum) and changed to a 4 blade Hyromotive labbed 24p prop from a labbed Bravo 4 blade repitched to 22p. The motor was also tuned up and had the valve springs checked and valves reseated.

Here are the results:

Hole shot improved, although not dramatically, the larger pitched prop offset some of the gains resulting from the spacer move, the larger diameter of the Hydromotive prop hooks up much better than the Bravo prop, doesn't spinout

Top speed went from 70.1 @5350RPM to 74@5100RPM, GPS (4 poeple, 1/4 tank of fuel, 80 degrees), nearly ran even with the 27' Fountain (HP500 Carb'd) I run with, not bad for a "Vista Cruiser with a big motor" as some of my Fountain buddies have called it

Cruising speed went to 50mph at 3800rpm, not sure what it was before but I am thinking it was around 43-45mph

Not exact, but fuel milage seemed to have went up dramitically at cruise, burned a lot less gas this weekend on the 70 mile round trip for dinner and drinks than usual

The guys I run with said it looked like a different boat at speed, the Hydormotive prop gives a lot more lift and bite than the Bravo prop, allowing more trim to better lift and fly the hull.

Should have some new pictures coming of the boat at speed

I am very happy with the money spent (bought the prop used at a fair price off of OSO also)

Thanks to OSO, it feels like I got a new boat for the summer

formula271

boatinbill,
I'm glad to hear the prop I sold you is working out for you. I picked up a 26p Bravo prop labbed by Merc. I have only had it out once and I picked up about 250 rpm with the holeshot was much better. As far as top speed the lake had some pretty good rollers that day so I didn't get to run wot for very long. Let me know if you do anything else to the boat this season.

boatinbill

formula271, I had forgot who I bought it from, thanks again it worked great. If you have not tried changing the position of the spacer at the back of the Bravo drive, do so, it really makes a difference in the holeshot. Just be sure to trim up once you are on plane, the extra negative trim the spacer change gives you could result in bow steer.

I can not remember if I told you this, but my motor got damaged sometime late in 2000 or in 2001 and was not diagnosed until last year. It endded up that I was down on power (and dropping slowing throughout the summer) for most of 2001. I had the Bravo prop reworked to get the holeshot and rpm's back in 2001. Once the motor problem was properly diagnosed and repaired I was bumping the rev limiter and down on speed. (obviously under propped)

The Hydromotive loaded the motor back to the rpm range I wanted and picked the extra speed due to the larger diameter and better bit. I am also sure that the cleaver blade shape allows me to trim more. My hole shot is just slightly better than it was with the Bravo, but I am sure that if I still had the Bravo on it would be great. I do know that I need to watch putting full power on take off as this prop does not spin out the way the Bravo did, this one is harder on the lower unit.

Now I am thinking that it is time to add a nose cone, my previous experience with nose cones in this speed range are that they allow to trim more and still keep a good prop bite. Knowing that the 271 hull wants to run wet, the extra trim and resulting bow lift should really help.

boatinbill

Sorry for the bad quality of the picture, will work on a better one. I know that throwing a big rooster tail is not the fasted route to go, but you have to admit that it looks cool. By the way, I was doing about 72mph in the picture, down a couple of MPH from the more neutral trim, but it made a better picture.

formula271

formulafastech,
Can you give me a quick explanation of what you did with the spacer? I remember you posted something about it but I don't remember exactly what you did. How's your boat running this year? Any changes to the motor or try any different props?

boatinbill

The spacer I was talking about and learned about last year from formulafastech is at the back of the outdrive where the trim cylinder bolt (shaft) connects the two cylinders to the outdrive.

If you take off one side and pull the bolt out, you will see that there is a slot in the outdrive with a rubber spacer in it. According to the Mercury Bravo One manual, the spacer is to be on the transom side of the bolt for Bravo One and Two drives and on the other (Rear) side for the Bravo Three drives (all three drives use the same upper housing).

On the 271 Fastech Formula has put the spacer in the Bravo Three position. The Bravo Three drive has greater transom lift with the duo props and does not need to tuck under as far to get the boat on plane.

I would assume that Formula did this to prevent bow steer if you did not trim up once on plane making the boat safer for the novice driver.

However what it effectively does is prevent the drive from trimming in as far, hence making the boat slower to plane.

Give it a try, it is amazing what that one inch in drive tuck will do on takeoff.