phragle

iTrader: (3)

Brett would give a better answer than Lorena.......

thirdchildhood

iTrader: (6)

That would get rid of most but not all of it. I just happen to have two Bravo 1 props on the dining table right now!

Does anyone have the length of a stock Maximus 5 blade? The shortened Max 5 is 7 1/2" with the diffuser removed. Yeah, I have a Max 5 sitting on the dining table also.

ThisIsLivin

Biggest problem I have run into with my Hydromotive without the diffuser is that I have to baby it getting on plane or it blows out bad. It doesn't like going slow at all, runs best above 45. In rough water going less than 40 it will lose grip and I have to pull back on the throttle till it grabs. After the rebuild, I make a lot more torque and I can blow out my labbed B1 30P with diffuser also, but it takes a lot more effort.

thirdchildhood

iTrader: (6)

What size boat? The Max 5 with no diffuser is said to jump on plane and have better performance across the board on the Donzi 22. It is recommended for small boats with bigger power. From Merc Racing web site: "Although MAX5 was targeted toward high-horsepower outboards, it also benefits applications with Mercury Racing 520 to 600 HP single and lightweight twin-engine sterndrive applications. Compared to the four-blade Bravo I, MAX5 offers quick hole shot with reduced slip percentages throughout the rpm range, increasing top speed 6-8% on average. MAX5 has a short barrel that minimizes stern lift and less blade area than the Lab Finished Maximus, allowing it to spin up and accelerate faster. …"

c0ncEpT

I'm curious how large of a difference removing the diffuser actually makes. I have a 27' Fountain that had a stock B1 30p with a full length diffuser. I picked up a B1 30p labbed to 29p with the diffuser cut way down. Haven't tested yet because of weather.

Mentalpause

I had 1/2" of my diffusers cut off when I labbed these B1s. Added a bit of cup, but mostly got all the blades the same in pitch and cup, which there was quite a bit of difference out of the box from Merc. Only difference I saw was carried the nose better. Getting on plane was the same, or at least not noticeably different. Maybe a slight difference in falling off plane 1-2 mph sooner, but I can still stay on plane down to around 24-25 mph.

87MirageIntruder

A traditional Max 5 does in fact have the diffuser removed, but keep in mind the tube is still quite long. So, you can still have some planing surface (tube) without the aggressive stern lift. They work great on a Nordic 28 Heat for example.

From what I understand, removing a diffuser can work well on boats that get onto plane easily, but have trouble carrying the bow. Good example is a long single engine like a 28'-30'. Not much weight in the stern (single engine) compared to the length/weight of the bow.

14 apache

iTrader: (1)

I removed them on my 33 apache it was a complete pig hardly would plane off and max speed was same.

Mentalpause

Yep. If you are not good at getting on plane, big mistake to remove them IMO.