Prop slip increase with speed.
01-07-2015, 03:53 PM
#11
Registered
Platinum MemberThread Starter
iTrader: (4)
I was looking at that. I have zero experience with nose cones. From what I read on hear it seem that the imco cone like to be near the surface, my drives are deep. For $107 it's worth a try. How deep were your drives and what kind of boat did you run it on?
01-07-2015, 05:29 PM
#13
Registered
Platinum MemberThread Starter
iTrader: (4)
This is my first boat with twins, so a lot of this is new to me. Here is another thing that happens about 63 or so and get worse with more speed. When trimmed out and WTO I need to slowly turn the steering wheel to keep the boat going straight. It can be as much as 1/4 to 1/3 of a turn. When I pull back on the throttles its a white knuckle experience, it feels as if it could hook up and dart, of course it doesn't but it is not a pleasant experience. I've always thought this was a clear sign that I needed external steering; however, the more I read posts it sounds like my drives may be blowing out. Does anyone have any input on this?
01-07-2015, 05:48 PM
#15
Registered
Platinum MemberThread Starter
iTrader: (4)
No idea- but I know it isn't 67 mph. There are guys with 90-91's with 502's and the modern bravo lowers and they are in the 70's. Mopower has a 272 that does over 80 mph. I'm no where near the hull speed of the boat. There is an issue somewhere, and the more I dig, the more I think its the lowers. I just don't want to spend the money replacing them only to find out it was another issue.
01-07-2015, 06:02 PM
#16
This is my first boat with twins, so a lot of this is new to me. Here is another thing that happens about 63 or so and get worse with more speed. When trimmed out and WTO I need to slowly turn the steering wheel to keep the boat going straight. It can be as much as 1/4 to 1/3 of a turn. When I pull back on the throttles its a white knuckle experience, it feels as if it could hook up and dart, of course it doesn't but it is not a pleasant experience. I've always thought this was a clear sign that I needed external steering; however, the more I read posts it sounds like my drives may be blowing out. Does anyone have any input on this?
Last edited by GPM; 01-07-2015 at 06:05 PM.
01-07-2015, 06:07 PM
#18
At that speed I don't think it is the lowers. My 272 is rock solid at 65. Is there any play in the gimbals? Or cable helm? The gimbals on the 272 were worn and I did not like it, i rebuilt them and good to go.
01-07-2015, 06:08 PM
#19
Registered
Join Date: Feb 2011
Location: Brookfield Wi
Posts: 771
Likes: 0
Received 0 Likes
on
0 Posts
This is my first boat with twins, so a lot of this is new to me. Here is another thing that happens about 63 or so and get worse with more speed. When trimmed out and WTO I need to slowly turn the steering wheel to keep the boat going straight. It can be as much as 1/4 to 1/3 of a turn. When I pull back on the throttles its a white knuckle experience, it feels as if it could hook up and dart, of course it doesn't but it is not a pleasant experience. I've always thought this was a clear sign that I needed external steering; however, the more I read posts it sounds like my drives may be blowing out. Does anyone have any input on this?
As far as slip - your tach's might not be accurate. The tach in my 1989 Mirage reads a few hundred high.
01-07-2015, 06:12 PM
#20
Registered
Talk to Tom at Hydromotive Props. I don't know if they still make it but they used to have a nosecone for the older Bravo One. They were designed to prevent blow out on the old style drives. Eventually Mercruiser changed the design and it wasn't needed.
