bert4332

I just swapped the in-line fuel filter, a few things you gotta be careful about. Mallory makes the best ones, see if you can find one, they are on back-order. Go and purchase two flare nut wrenches, if you don't you might strip the nutz, I purchased a Wix 33481, the problem was I couldn't get the flare nuts to seat all the way and it was leaking. So for $40 more I purchase the Merc, what a POS. Be very careful even just tightening snug, you have to have equal pressure with both hands on the wrenches or you will bend the stem at the weld. So I went back to the Wix and used some gas approved thread tape and all is good.

What props are you running? My engine bangs right up to 5900 no problem.

verbi69

Bert,

Thanks for the heads up, I have not done this before and I am looking to do it the next couple of days, so any advice or hints is much appreciated.
I'm running 5 blades, cant remember the make at this time though, I think Hydromotives.
The first weekend out I was able to spin the engines to 5200 rpm, but not this time....I wonder how much tab input plays into effect?

bert4332

I would imagine tab placement is huge, This is what I did when I got my Lavey. I tucked the drive down as far as it can go, push the tabs down as far as they go and went out of the hole from there. I brought the tabs up to -1 just down a little in the water, 0 being even with the hull, then I moved my trim settings up from there, as big as the V is on that monster I would imagine both the tabs and trim settings can really have a big impact on digging the bow into the wave. When I got to my sweet spot, boat is balanced nicely, I just experimented by tapping the trim up a tiny bit at a time, and watching my tach at the same time. You'll see your rpm's jump when you trim up too much. Or you can drop the tabs down a lil and keep the trim high and see how the tach reacts. I'm STILL playing with mine, I think it takes one good summer to really learn a boat.

After writing this I realized I'm way over on my RPMs. I 5350 is the limit, I gotta figure out what's up with mine going past that.

Need4SpeedGTCS

Verbi,

I went from 32" five blade hydromotives only pulling 4800 to 30" four blade bravos now hitting 5500 (recommended by whipple) I never had a chance to run WOT but my tech confirmed max rpm. Between the 4 & 5 blade props I found a huge difference to get on plane. The 5 blades would get me out of the water with almost any drive/tab setting; the 4 blades are a really sensitive and blow out easy. Will probably have some work done to these 4 blades.
Anyway, in good water to get on plane you should be able to pull the drives all the way in and drop the tabs about half. As you're coming up start bringing the drives out and tabs up. Get the tabs fully up then tweak the drives to that sweet spot. I run really flat with zero tabs in good water.
Although no top end run had a great weekend, lots of sun and bikinis at the lake! GF has pic's on her camera...will post some soon!
Also, turfed my CD changer and replaced the Sony head unit. went with a Sony Xplod unit again...connectors were identicle so it was 'plug & play'. New Xplod unit has a 'tune tray' holds the ipod inside, all my tunes with no CDs or bulky changer taking up space!

verbi69

I am totally impressed on how easy the boat gets on plane with the 5 blades.....very quick out of the hole with some tab.
Lifting the tabs all the way up I can feel the nose of the boat free up, these things do ride flat though.
It seems that the boat really likes to have a lot of trim.....like I'm talking maxing trim (without using the trailer).
Need4Speed,
How did the new power feel otherwise??
I havent tried the 4 blades yet, but I do intend on trying them

Need4SpeedGTCS

There was such a difference coming out of the hole (blow out) with the props that it was hard to tell how the engines were running. The did purr along fantastic but just never got to run wide open; never even saw the boost gauges move. Will probably have these props cupped or go back to 5 blades with different pitch.

Knot 4 Me

What 5-blades are you running? If they are Maximus you can cut the diffusers off to help eliminate some of the stern lift. 4 blades with a lot of cup will help carry the bow. Then lab them to get the RPM back you will lose with the extra cup.

verbi69

The 5 blades that I am running are the Hydromotives.
Cutting the diffuser will plant the rear neading less trim I'm guessing?
Sounds like a good idea to do the cupping and lab work on the 4 blades.

Powerful Addiction

Verbi,

Remember what I told you about the 5-blades. They were built for cruising efficiency and not top speed. The four blades are the speed props and they have already been tuned / cupped to get that boat at top speed. You will need the trim at almost 8 on the gauge and the tabs set at 2.5 on the gauge ( flat with the boat bottom ). If the water is a washing machine that is what the boat loves most and if you have that condition again you will have no issues topping 85 mph with 4 people and full of fuel running the 4 blades. The five blades were made to get the ass our of the water already so any adjustments will make it worse. The high pressure filters are two seasons old - it will help to change them.

Tim

verbi69

Tim,
I have no desire to touch the 5 blades, they work really nice pulling the boat out of the water, you did a nice job setting them up.
I wasn't aware the 4 blades were worked over, that is really good to know.
How different does the boat get on plane with the 4 blades compared to the 5 blades?