2007 35 executioner prop question
 

I'm in the process of buying a 2007 35 fountain executioner with 496 HO. it has 1.65 drives with a 32 5 blade. on the surveyed test drive it had full tanks with 3 adults. the boat only ran 72 mph at 4400rpms WOT. the drives were at 4.5 and tabs at 2. is this normal with the 32 5 blade or does the drives just need to be trimmed higher. I was told it should run 78-80

Call Fountain with the hull number and they will fax you the test run sheet that has the speed they achieved and the props used.

I already did that it had the bravo 4 blade 32 ran 79 at 5150. The prop has been changed to a 5 blade 32

You are putting a tremendous load on those engines if 4400 is WOT , I have the same boat with the same motors and I had BBlades make a set of 34 Bravo 4 blades that are lab finished . The best I have seen is 80 @ 4950 and the tabs all the way up drives @ 5

I think all the Fountain reports are a little on the happy side,
I am new to the 35 EX myself,but talking with other 35 owners I have been told the boat is a true 75MPH boat and when all the planets and stars line up that one day you might see a honest 80, but expect 75,hopefully I am wrong and with the right props we might see 80.

I'm not worried about the speed I guess what I'm asking is should I be able to turn 32 5blades closer to 5000rpm or when you go to 5 blades do you need to go to 30's

Can you ask the previous owner why it had 5 blades on it? The 32 four blade props are the correct ones for the boat with a 1.65 ratio. Sounds like the 5 blades were an attempt to improve mid-range speed, but certainly not top end. As you can see with the 5 blades and all that weight on the test run, the engines didn't have the steam to deal with the load. You would have to drop pitch on the 5 blades to get closer to the proper WOT for those engines. I'd go back to the 4 blade 32 Bravo 1's as that is the perfect prop for the 35 Ex. I've been in 3 different ones and they all ran 32 four blades with 1.65 drives. Depending on gear, fuel, persons on board you should see 76-78 at WOT of about 5000-5100. A stock 35 Ex with 496's is not an 80 mph boat.

techman is right on the money here. Spot on with the info he has put out for you.

The tall gear boats were a tick faster on the top end, did give up some in getting there vs the 1.50 geared boats.

He said it was running on the limiters and he wanted a better cruising speed.

That's what I thought. Propping is always a compromise!

So do you think it's normal to drop that many Rpms going from a 4 to a 5 blade. Drive trim was only at 4.5 so I'm thinking it will turn up a little more. I'm just trying to make sure that is normal and not something wrong. I had the motors scanned and compression test and all was good.

Look back to the test report fountain sent you and see where they had tabs and trim.

Most fountains 3 is neutral (even with bottom of boat).

While it is on the trailer confirm that using a long level. You need to make sure that the cables are adjusted correctly before you get to far into this.

Yes, adding a blade can have a dramatic effect. Refer to the original Fountain report for trim settings as they are usually spot on. At 4.5 you are pretty close to max trim I would guess. Anymore trim and you will start surfacing the prop, losing bite, and putting strain on the u-joints, for little or negative gains.

Personally, I would get rid of that 5 blade and go back to the stock props or work with a prop shop, like BBlades and determine your performance goals. But to be honest there isn't going to be a magic trim setting or prop that will get you anymore top speed without adding HP. I am firm believer in trusting what Fountain determined was the best setup for their hulls and power train when it left the factory. If you have a stock setup and no plans to modify your engines and drives, find yourself some 32 Pitch B1 four blades and enjoy!

Lots o'chit to come into play here. What 5 blades? Stockers or modded? What diameter? You need to know exactly what you are working with before you can figure where you need to go. I have 32 four blades that turn 5400 every day, I have 30 five blades that turn 5400 every day, I have some real wild modified 31 five blades that I have never turned past 5000 but still run within a couple mph of my best top number. I have tested props, four blades and five, from 29 to 33 and they are all over the map. Actually tested a set of five blade 33's that I put on the limiters. Go figure.

Like techman said, get yourself a set of 32 Bravo four blade stockers, note the stocker not been f'd with, and get some baselines. They will be real close.

I have tried 2 sets of 32 Bravos and both hit the rev limiter and the best I have seen is 75 on GPS,I am thinking of trying a set of Hydromotive 30s 4 blades,
Hydromotive was always the props Fountain sold their boats with and I thought they ran great,
They switch to Bravos once Fountain and Mercury got together so I am not sure if they switched to Bravos because they ran better or because they partnered up. anybody ever try Hydros on a 35 EX?

I've got a set of 32 Bravo I's for sale in excellent condition.

I'm not sure what kind these are. I was told he got them from BBlades. I'll stick with these for now. The cruise speed was perfect for me. I'm willing to give a few on the top end for that. I think I may get a little more out of it by trimming the motor a little more. I just have to wait a few more days to pick it up and find out.

If you can only pull 4400 rpm max, even cruising at a lower rpm is still lugging the motors and it will wear them out in a hurry.

Our 03 - 35 EX, W/32s 496s, tab 3, trim 5.5, 78 mph on gps, 2 people, full tanks so ma bee + 1 w/1/2 tanks

does it need time to get to 78mph or does is get there pretty quick?

I might need to try another set of 32s

70-72 pretty quick and the rest comes reasonably fast with some chop , flat water takes a bit longer

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Is that fresh or salt water?