User Tag List
Thanks: 0
Results 1 to 15 of 37
Thread: Lower unit leading edge
-
12-25-2020, 10:19 PM #15000 RPM
- Join Date
- Mar 2013
- Location
- Sunshine Coast, Queensland
- Posts
- 186
- Thanks (Given)
- 0
- Thanks (Received)
- 6
- Likes (Given)
- 1
- Likes (Received)
- 47
- Mentioned
- 0 Post(s)
- Tagged
- 0 Thread(s)
Lower unit leading edge
Gidday guys, merry Christmas to you all, hopefully 2021 will be a better year than 2020 for everyone
For a long time now, I have been battling a V-shaped spray coming from my lower unit until I trim out a fair bit. Using the boat for water skiing, this of course
makes the wake a bit unpleasant for barefooters. I have tried raising my engine, I have experimented with the bottom of the hull, only thing left to try
is my lower unit leading edge. It's in good shape, just fairly thick. Does anyone actually fair or sharpen the leading edge of their lower to improve the water
flow over it? The only thing I can think of now, is that being fairly thick it's "pushing" through the water rather than "cutting" through it, causing the spray
A/V plate is just above the waterline while running
Anybody offer any advice?
-
12-26-2020, 01:18 AM #2
IVe experienced this spray as a skier it’s not fun at all. I was pretty young but we solved it with a different prop. I didn’t see mention of props
Hydrostream dreamin
-
12-26-2020, 06:07 AM #35000 RPM
- Join Date
- Mar 2013
- Location
- Sunshine Coast, Queensland
- Posts
- 186
- Thanks (Given)
- 0
- Thanks (Received)
- 6
- Likes (Given)
- 1
- Likes (Received)
- 47
- Mentioned
- 0 Post(s)
- Tagged
- 0 Thread(s)
I have tried different props, doesn't really make any difference. It's not coming off the back of the lower (ie prop), but definitely the leading edge.
-
12-26-2020, 06:49 AM #4
Plenty of guys shape the skeg especially after damage. You have to be careful with it though that’s your boats entire steering control. I can’t see a reason not to file it sharper to try and help this issue. Post a pic or two helps
Hydrostream dreamin
-
12-26-2020, 03:52 PM #55000 RPM
- Join Date
- Mar 2013
- Location
- Sunshine Coast, Queensland
- Posts
- 186
- Thanks (Given)
- 0
- Thanks (Received)
- 6
- Likes (Given)
- 1
- Likes (Received)
- 47
- Mentioned
- 0 Post(s)
- Tagged
- 0 Thread(s)
-
12-26-2020, 06:27 PM #66000 RPM
- Join Date
- Feb 2011
- Location
- HUDSON, FLORIDA
- Posts
- 1,528
- Thanks (Given)
- 427
- Thanks (Received)
- 63
- Likes (Given)
- 433
- Likes (Received)
- 450
- Mentioned
- 1 Post(s)
- Tagged
- 0 Thread(s)
-
12-26-2020, 08:20 PM #75000 RPM
- Join Date
- Mar 2013
- Location
- Sunshine Coast, Queensland
- Posts
- 186
- Thanks (Given)
- 0
- Thanks (Received)
- 6
- Likes (Given)
- 1
- Likes (Received)
- 47
- Mentioned
- 0 Post(s)
- Tagged
- 0 Thread(s)
Unfortunately no, it's not the hull. I have hung over the back and observed a few times, and even tried modifying the bottom of the hull
temporarily (outboard is on a built in pod/extension, the bottom of which is angled up slightly) by gluing on nylon plates to make the
hull/pod extension level.
A couple of photos I have on file, you can't see the leading edge of the A/V plate, but it is about 1/2-3/4" above the water line. Looks like water is coming off the lower unit leading edge
heading up then the spray deflector shoots it out into a V. Got me buggered what's going on.
-
12-27-2020, 12:25 PM #86000 RPM
- Join Date
- Feb 2011
- Location
- HUDSON, FLORIDA
- Posts
- 1,528
- Thanks (Given)
- 427
- Thanks (Received)
- 63
- Likes (Given)
- 433
- Likes (Received)
- 450
- Mentioned
- 1 Post(s)
- Tagged
- 0 Thread(s)
Why cant you see the cav plate if you say its above the water? what i see in the pic, cav plate is submerged. motors set too low always make that v spray. i did some barefooting, i my youmger years, boat spray is like skiing in a rain storm. you say you raised the motor and still have the spray?
-
12-27-2020, 12:34 PM #9
Spray culprit
Do you have one of these?
\\\/// \\\/// \\\/// \\\/// \\\/// \\\/// \\\/// \\\/// \\\/// \\\/// \\\/// \\\/// \\\/// \\\/// \\\/// \\\/// \\\/// \\\/// \\\///
Checkmate Pulsare 2100 with a 2017 Merc 250 Pro XS
-
12-27-2020, 12:35 PM #10
We used to call them the torque tab. Helps negate the lower unit trying to turn. Also can make spray at the right height.
\\\/// \\\/// \\\/// \\\/// \\\/// \\\/// \\\/// \\\/// \\\/// \\\/// \\\/// \\\/// \\\/// \\\/// \\\/// \\\/// \\\/// \\\/// \\\///
Checkmate Pulsare 2100 with a 2017 Merc 250 Pro XS
-
12-27-2020, 05:37 PM #115000 RPM
- Join Date
- Mar 2013
- Location
- Sunshine Coast, Queensland
- Posts
- 186
- Thanks (Given)
- 0
- Thanks (Received)
- 6
- Likes (Given)
- 1
- Likes (Received)
- 47
- Mentioned
- 0 Post(s)
- Tagged
- 0 Thread(s)
You can't see the cav plate because the water being pushed up by the leading edge is shooting past it obscuring it. It is not running underwater, even with the engine raised far enough that I can put my finger under the A/V plate while running, the spray is still there.
I reckon it is because the leading edge of my lower is fairly blunt, until I trim out, the leading edge is angled forward and the leading edge is pushing the water up. Once I get past neutral trim, it no longer pushes it up.
That's why I was asking about trying to fair the leading edge of my lower, so I don't have a flat (albeit narrow) surface ploughing through the water and pushing water up until it hit's the spray deflector, shooting out into a V.
That's the best theory I can come up with!
As far as skiing/footing goes, it doesn't spray back very far, but is more of a pain for my observer. I want to raise my engine further just to optimize my performance, just trying to get rid of the V-sprayLast edited by wettek; 12-27-2020 at 05:39 PM.
-
12-27-2020, 05:41 PM #125000 RPM
- Join Date
- Mar 2013
- Location
- Sunshine Coast, Queensland
- Posts
- 186
- Thanks (Given)
- 0
- Thanks (Received)
- 6
- Likes (Given)
- 1
- Likes (Received)
- 47
- Mentioned
- 0 Post(s)
- Tagged
- 0 Thread(s)
-
12-27-2020, 07:13 PM #135000 RPM
- Join Date
- May 2016
- Location
- keys
- Posts
- 795
- Thanks (Given)
- 31
- Thanks (Received)
- 45
- Likes (Given)
- 254
- Likes (Received)
- 424
- Mentioned
- 0 Post(s)
- Tagged
- 0 Thread(s)
Motor too low.
ANTI40It's just an idea.
-
XstreamVking liked this post
-
12-27-2020, 07:30 PM #145000 RPM
- Join Date
- Mar 2013
- Location
- Sunshine Coast, Queensland
- Posts
- 186
- Thanks (Given)
- 0
- Thanks (Received)
- 6
- Likes (Given)
- 1
- Likes (Received)
- 47
- Mentioned
- 0 Post(s)
- Tagged
- 0 Thread(s)
-
12-28-2020, 07:25 AM #155000 RPM
- Join Date
- May 2016
- Location
- keys
- Posts
- 795
- Thanks (Given)
- 31
- Thanks (Received)
- 45
- Likes (Given)
- 254
- Likes (Received)
- 424
- Mentioned
- 0 Post(s)
- Tagged
- 0 Thread(s)
-
Similar Threads
-
Leading edge
By bigbluechevy454 in forum General Boating DiscussionReplies: 3Last Post: 10-02-2012, 06:22 PM -
Thanx Leading Edge
By Marko in forum General Boating DiscussionReplies: 2Last Post: 06-16-2008, 11:19 AM -
thanks leading edge
By rollin in forum General Boating DiscussionReplies: 11Last Post: 10-04-2007, 09:18 PM -
Leading edge cup?
By Carter Powell in forum Technical DiscussionReplies: 6Last Post: 02-05-2006, 11:06 AM -
File leading edge of lower Unit?
By Dregsz in forum Technical DiscussionReplies: 2Last Post: 06-15-2005, 07:53 AM