www.iFourWinns.com

I only purchased the V338 in June so I am still learning the boat. The boat is a 2009 V338 with Volvo 5.7GXi with DP. One thing I am struggling with is the proper trim of the boat. I’ve disabled the EVC trim control so I can figure out what I need. Coming on plane the drive trim is at -7 degrees without trim tabs down. As I get on plane and slow back to about 3500 RPM, I’m doing 25MPH and all feels OK, but everything I read I should be at about 31 mph. Then as I try to trim the drives to get better performance . . I can see that I’m making things worse since the boat is slowing and I then fall off plane when I get to about 3 degrees. All summer I’ve just been running it at the -7 since it does fine there . . . but my fuel economy is not what I think it should be. I have no idea if someone changed the props . . that is the only thing I can think of – cause this boat really jumps out of the water coming on plane.

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2010 Vista 338 Volvo Penta
2005 Yamaha Wave Runner FX HO

2005 SeaRay 280 SunDancer
2001 SeaRay 245 Weekender

I have a V328, essentially the same boat I believe. I don't know about degrees, but I also have the same power that you do. I can tell you that I can get up on plane at 3K to 3200 rpm with full fuel and water and 2 people with no effort at all, and up on plane with 10 people half fuel and water at 3200 to 3400 rpm, again with no problem and within about 100yards. I do NOT firewall the throttles to do this. This is with the drives all the way down and NOT using the trim tabs. Unfortunately I do not know the propset I have--just the factory issued ones to my knowledge
Once up, I often leave the drives down, but do find that it bow steers a bit and rides "wet" in even 2 footers (I'm on the ocean). If I trim the drives up just for a second (or two at the most) I pick up about 2 mph and it rides drier too. This is all about 25 to 28 mph.
The boat holds plane well at 3000 rpm in most seas and heavily loaded, but 3200 rpm is much nicer and the boat and motors just "feel right" at 3200 rpm no matter what the load. I seldom go to 3400 rpm--just no need to do so. My boat has @ 825 hours on it, fyi
Sorry I can't be more exact but hope this helps!

I have the same experience as above. Same engines and 3000 rpm on plane no problem. Are you sure your trim tabs are in the horizontal position and not pointing Down. I would push them to the bow up position and make sure they are operational.

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2001 328 Vista "Nauta Dream 2"
AB Inflatable 10AL "Little Dreamer"
2000 248 Vista
1997 225 Sundowner


Mike

VolDad,
I wonder if your propset is too small. That would account for why you need 3500 rpm to get on plane as you state. I could also account for poor economy. You also state it "jumps out of the water"--not sure what that means--if it gets on plane quickly or it you get a lot of bow rise, or both. It SHOULD jump out of the hole if you turn 3500 rpm or more to get on plane IMHO. FYI, I get about 1.1 to 1.2 mpg. Check what number propset you should have, then call your dealer or 4 Winns and see what it came with--maybe it has been changed and is too low

Also, are you fresh water or in the ocean? That could account for a bit of it too--fresh water is a bit less dense that salt water and could make you need a little more power to perform as my boat does. I used to notice about 1 to 2 mph difference and 1 to 2" of waterline differnce between salt and fresh water with my prior Sea Ray 268 Sundancer (it sat lower and was slower in fresh water)