Can I shorten my cavitation plate an inch or so? Bravo III

Alwhite00

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Would like to shorten the tail end of the cavitation plate on my Bravo III? It hits my extended swim platform when in the trailer position.
 

Slip Away

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Re: Can I shorten my cavitation plate an inch or so? Bravo III

I wouldn't take an inch off it. It's that length for a reason. Raise outdrive a bit less, or put rubber piece on underside of swimplatform
to cushion it while trailering.
 

MH Hawker

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Re: Can I shorten my cavitation plate an inch or so? Bravo III

Or cut out a notch on the swim platform
 

Alwhite00

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Re: Can I shorten my cavitation plate an inch or so? Bravo III

Or cut out a notch on the swim platform

It would need to be a half moon so if the drive is turned, not an option. Is there a way to limit the trailering upper limit?
 

UncleWillie

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Re: Can I shorten my cavitation plate an inch or so? Bravo III

... Is there a way to limit the trailering upper limit?

The upper stop is where the Hydraulic Rams run out of stroke.
If you opened up the Rams and installed custom made spacers, it would limit the stroke.
This is likely more than you are willing to do.

Otherwise, raise the drive to the Trim Limit switch, then hit the Trailer UP Button and count how long it takes to hit the platform.
Next time, release the button a second earlier.
 

tomdinwv

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Jun 22, 2008
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Re: Can I shorten my cavitation plate an inch or so? Bravo III

Do you have a remote switch on the transom to trailer the drive? Easiest thought that comes to my mind would be to trim up to the limit switch when pulling boat from water and then put it in trailer position with the remote switch while watching it closely. That's assuming the ramp(s) you use will allow your OD to clear at the limit switch.
 

GA_Boater

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Re: Can I shorten my cavitation plate an inch or so? Bravo III

You could add a trailer switch on the stern somewhere so you can stop the outdrive before hitting the platform.
 

Georgesalmon

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Re: Can I shorten my cavitation plate an inch or so? Bravo III

You could put an external stop on the ram. Use some kind of very thick like an inch thick plastic like nylon and using a hole saw drill the inner hole to match the outside diameter of the ram. Then using a larger hole saw cut the outside as big as you need. ( actually do the outer diameter first) Then cut in half put over the ram and clamp with a hose clamp or better put a couple of SS screws in it. Back in my youth we had a tractor with stops on the rams so we could adjust the depth of our cultivator and make it return to the same depth after we raised it to make a corner at the end of the rows.
 

smokeonthewater

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Re: Can I shorten my cavitation plate an inch or so? Bravo III

You could put an external stop on the ram. Use some kind of very thick like an inch thick plastic like nylon and using a hole saw drill the inner hole to match the outside diameter of the ram. Then using a larger hole saw cut the outside as big as you need. ( actually do the outer diameter first) Then cut in half put over the ram and clamp with a hose clamp or better put a couple of SS screws in it. Back in my youth we had a tractor with stops on the rams so we could adjust the depth of our cultivator and make it return to the same depth after we raised it to make a corner at the end of the rows.
That would only work to limit down stroke...... The. correct fix as mentioned earlier is to put spacers inside the cylinders.... Really not that bad of a job.
 

Alwhite00

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Re: Can I shorten my cavitation plate an inch or so? Bravo III

That would only work to limit down stroke...... The. correct fix as mentioned earlier is to put spacers inside the cylinders.... Really not that bad of a job.

I am looking into that option.
 

H20Rat

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Re: Can I shorten my cavitation plate an inch or so? Bravo III

Personally if it were me and it was only an inch, I'd probably be out the driveway with an angle grinder... Although I can't guarantee it, I suspect you would never notice a difference.
 

tpenfield

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Re: Can I shorten my cavitation plate an inch or so? Bravo III

I'd go the spacer route instead of cutting the drive. . . Resale value to think about.
 

H20Rat

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Re: Can I shorten my cavitation plate an inch or so? Bravo III

I'd go the spacer route instead of cutting the drive. . . Resale value to think about.

A little prep to make sure it is straight, a little angle bevel to match factory, and some black enamel paint, and you won't be able to tell it wasn't factory. (at least without looking at another drive side by side.)

I've shortened skegs that had a notch knocked out from a rock... Impossible to tell they weren't that way before, and in that case, shortening it HELPS resale!
 

bilge rat jim

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Re: Can I shorten my cavitation plate an inch or so? Bravo III

Simply shorten your trailering clips by 1 inch. Raise the drive until it almost touches the swim platform, install the clips, and lower the drive until the weight is on the clips. You DO use trailering clips, right?
 

Alwhite00

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Re: Can I shorten my cavitation plate an inch or so? Bravo III

The problem is seeing the drive. It's impossible to see it when in the water as the platform extends out way over it. I believe I could make it look like factory with a little grinding & file work and a coat of paint. I'm going to get a couple measurements before I do anything.
 

airshot

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Re: Can I shorten my cavitation plate an inch or so? Bravo III

Do you really need the outdrive all the way up in the trailering position? On my boat just the trim up position is more than enough height, never use the trailer position, easier on the bellows that way....just a thought.
 

haulnazz15

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Re: Can I shorten my cavitation plate an inch or so? Bravo III

Simply shorten your trailering clips by 1 inch. Raise the drive until it almost touches the swim platform, install the clips, and lower the drive until the weight is on the clips. You DO use trailering clips, right?

I'm not sure why you are placing so much emphasis on trailering clips. It's perfectly fine to tow without them, and the majority of people do.
 

Fun Times

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Re: Can I shorten my cavitation plate an inch or so? Bravo III

Do you have a one or two piece bravo 3 gear housing?

http://www.mercruiserparts.com/Show...sc=GEAR+HOUSING(BRAVO+III)(ONE+PIECE+HOUSING)

http://www.mercruiserparts.com/Show...sc=GEAR+HOUSING(BRAVO+III)(TWO+PIECE+HOUSING)

Merc also has a trim up spacer kit just for this problem.
Item # 28 15768A3 SPACER KIT, Up (SPACER KIT-TRIM CYLINDER) $10.80 $10.54 QT,1
http://www.mercruiserparts.com/Show...=260&bdesc=TRIM+CYLINDERS+AND+HYDRAULIC+HOSES

Another idea would be if you know your boat well enough and you don't rely much on your trim up limit switch from stopping you from over trimming the drive while underway, then you could also try readjusting your trim up limit switch so it stops short of hitting the platform and just use your trim button vs trailer button.

Trailering clips are a preference for cheap insurance for when the unthinkable happens! .... and it does happen. But in this case the idea is to prevent the drive from hitting something while trimming up sight unseen along with other possible distractions going on in turn affecting someone's timing judgment of when to stop before it's too late. The trailering clips would only seem to come into effect only after accidentally raising the drive a bit to far up before lowering the drive back down.

PS, It's always good practice to just slightly "bump" the trim button down once you get to the full up position. It takes the heavy load of the hydraulic pressure off the trim system while leaving plenty of pressure to keep the drive in the up position.
 

Alwhite00

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Re: Can I shorten my cavitation plate an inch or so? Bravo III

2 piece. Thanks for all the info. if I do anything it will probably be the spacers. anyone ever take one of the cylinders apart?
 

haulnazz15

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Re: Can I shorten my cavitation plate an inch or so? Bravo III

I still don't see why you'd want to modify anything. The cheapest/simplest solution is just not to trim the drive so far up. It's along the lines of what to do about the gas mileage being so bad at full throttle . . . the solution is to not run at full throttle.
 
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