GLF Posted September 12, 2007 Share Posted September 12, 2007 This is a question for members who keep their boat slipped in the water all season.At the start of the season, top speed on my boat was 35mph at 4,400RPM. Now I am only getting 30mph at 4,400RPM. I still cruise at 24 mph at 3,600RPM. I have not hit anything, and there is no vibration. I put a new coat of bottom paint on the boat during the winter. Untill the boat is pulled, I will not know if there is any build up on it. Looking at the outdrives, I can see a build up on them. If you have I/O(s), do you put bottom paint on your outdrive(s)?Is your boat going slower now than at the beginning of the season? Link to comment Share on other sites More sharing options...
special x Posted September 12, 2007 Share Posted September 12, 2007 Sounds like you may have gained some weight. Check your water line. I tell my customers to mark it in spring and then check it over the summer . this will tell you if you have gained any water absorbion. Also a person tends to loss track of all the misc stuff that gets brought on board . Yes fouling can lower speeds . Some one does make a fouling paint just for outdrives will post it when i find the name. Leroy Link to comment Share on other sites More sharing options...
Priority1 Posted September 12, 2007 Share Posted September 12, 2007 I noticed my hull was dirtier than normal after my Muskegon trip. I'm not trying to imply anything, but I do think the build up on all hulls is greater near large industrial cities. Even the natural stuff on hulls will sloooooooow U down. Link to comment Share on other sites More sharing options...
Dv8oR Posted September 12, 2007 Share Posted September 12, 2007 Is your boat going slower now than at the beginning of the season?Did the trims work on the motors at the beginning of the season.I'll guarantee ya, with them in the full "in" position like they are, your not going to go as fast as you were.....You can't bring your bow up with the trims stuck at full "in" or "down"...You could probably use your trim tabs to help compensate a little but not as much as the motor trims...... Link to comment Share on other sites More sharing options...
GLF Posted September 12, 2007 Author Share Posted September 12, 2007 I'll guarantee ya, with them in the full "in" position like they are, your not going to go as fast as you were..... They are not in the full "in" position. I always left them the trimmed up, for max speed. I have to run a little faster to keep it on plane in the position they are in. They are in the same position now, as they were at the start of the season when I was getting 35mph. I looked at my neighbors boat hull below the water line. He has bottom paint on his boat. I could see what looked like close to a 1/2" of fouling. I thought with the anti-fouling paint, it was suppose to prevent this. Link to comment Share on other sites More sharing options...
Richard Posted September 16, 2007 Share Posted September 16, 2007 GFL,Many things effect the ability of your boat to maintain its speed. The debree or film on the bottom of your boat is a contributer. The weight of your boat will also effect the speed if you are collecting water there may be a problem.The main situation I think you are seeing is due to the density (sp) of the water. Water is densest (sp) at I believe 39 deg. F. I find that fully rigged the week before I make the trip up to Lake Ontario I can obtain 42 mph on a home lake. When I arrive at port and run out on a flat calm day I can only obtain about 33 mph. I have spoke to many people about this situation and we have all agreed.Good luck and tight lines.Richard Link to comment Share on other sites More sharing options...
Walleye Express Posted September 27, 2007 Share Posted September 27, 2007 I painted both of my outdrives (along with the bottom) for the first time last spring. I was very surprised 2 weeks ago when I pulled my boat and seen how clean they were from previous years. I even noticed that the Zebra Mussel clusters were down by I esimate 70%. But was told everybodys was down for this year. Seems our Goby population is thriving on them. But all hulls obsorb water to a degree as they set. Thus more drag, weight and water friction. Link to comment Share on other sites More sharing options...
Take Six... Posted October 16, 2007 Share Posted October 16, 2007 Extra weight and even a little slime over the entire surface which contacts the water could easily knock 5 mph off. What caught my eye was WOT rpm of 4,400. I had a 1990 Carver Montego for nine years with Merc 350 cu.in. V-8. I'm almost sure I was spinning 4800 - 5200 range. Plus if your spinning an aluminum wheel, those blades flex a considerable amount under load and litterally flatten out. You can increase your rpm by 200 revs for every 1 inch of smaller prop pitch. Pitch is the theoretical distance of how far the prop will travel in one revolution. Lower pitch gives more torque. I'm no mechanic 4,400rpm seems like the motor is working too hard. Also, check your prop for pitting. A pitted prop can induce cavitation across a greater blade surface. It would be caused by stray current and electrolysis under water. Make sure your grounding anodes are in good shape. (Ask Santa for a S.S. prop) Link to comment Share on other sites More sharing options...
Walleye Express Posted October 19, 2007 Share Posted October 19, 2007 Take Six. That is some really good poop and info. Link to comment Share on other sites More sharing options...
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