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blocking off water pickup for speed gain

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Old 02-22-2011 | 08:52 PM
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Default blocking off water pickup for speed gain

Has anyone ever welded up the low water pickup on a 2" shorty imco and used a transome water pickup? On my outdrive a 1/2" behind the pickup, for maybe 1 1/2" long & 1/2 wide, it's starting to ech out the aluminuim. it didn't start this till my new HP and my speed's hit 100. my prop slip % is going up after 95. im kinda thinking the pickup is thowing a bubble and it's burning the aluminuim (couseing the eching) and putting a bubble to the prop couseing the extra slip.

Has anyone ever tried this and gained?
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Old 02-22-2011 | 10:16 PM
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From: Between A Womans Leggs in IL
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Originally Posted by Bill Mattingly
Has anyone ever welded up the low water pickup on a 2" shorty imco and used a transome water pickup? On my outdrive a 1/2" behind the pickup, for maybe 1 1/2" long & 1/2 wide, it's starting to ech out the aluminuim. it didn't start this till my new HP and my speed's hit 100. my prop slip % is going up after 95. im kinda thinking the pickup is thowing a bubble and it's burning the aluminuim (couseing the eching) and putting a bubble to the prop couseing the extra slip.

Has anyone ever tried this and gained?
Thats a common problem,try a 1/2 '' spacer and see if it goes away,your drive height may be a touch to high.
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Old 02-22-2011 | 10:23 PM
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Mine is etching too and my drive height is good. My boat runs average of 83 mph.
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Old 02-23-2011 | 04:55 AM
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If you do stop the water flow through the drive it will cost you in drive cooling. They depend on the water flow through them to keep temps down. You can go to an external cooling system, but dont run that drive without water going through it.
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Old 02-23-2011 | 07:30 AM
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Originally Posted by Mr Gadgets
If you do stop the water flow through the drive it will cost you in drive cooling. They depend on the water flow through them to keep temps down. You can go to an external cooling system, but dont run that drive without water going through it.
I've been told that by others so I concur. I have also been told that the cavitation causing the etching is unavoidable so I guess these gear cases have a limited life span.
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Old 02-23-2011 | 09:39 AM
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This might sound crazy but...

What about having the lowers plated with something like a chrome plating from a chrome shop, etc., etc.

It seems to me that a solid chrome plating job would not only look awesome, but it might be more durable than just the raw aluminum casing.

I will say that I personally have never experienced this problem!
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Old 02-23-2011 | 10:21 AM
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Originally Posted by Mr Gadgets
If you do stop the water flow through the drive it will cost you in drive cooling. They depend on the water flow through them to keep temps down. You can go to an external cooling system, but dont run that drive without water going through it.
Do you think it would be worthwhile to try to plug the hole near the prop and open one higher up the lower? I realize the drive needs water through it, but I wouldn't think it needs water through it that low. It seems like the water that the drive is in should be enough to keep the lower cool, at least down by the prop.
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Old 02-23-2011 | 11:28 AM
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Interesting. Hawkeye Marine plated some Bravo lowers but I don't know how they held up.
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Old 02-23-2011 | 02:08 PM
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Thank's for the info so far, mine look's just a little worse than the thirdchildhood's picture, i also was thinking of closeing the pick up off just a little becouse it already is bigger than the oppening in the sea water pump. i just thought sence speed master's didn't have a pickup at all there was a reason for it. and i understand the cooling part. Thank's again
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Old 02-23-2011 | 02:12 PM
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O-Yeah forgot to say. i did coat the whole unit in grafite and sanded it smooth. along with a little shape mod's. it gained me 2mph but the spot reburned off.
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