Mark, how much extra length do your bolts have at the moment. The 3 degree wedge is not so thick at the top but the 5 degree one is. Be aware that wedges also have the effect of lowering the cav plate a little, especially if your transom already has some negative. No big deal, just be aware in case you get spray and need to lift. You might find you want to try both the 3 and 5 but I'd start with 5. http://www.overtons.com/modperl/product ... 009&r=view You can see it adds about 1 1/16" to thickness so top bolts will need to be long enough. Bottom bolts will probably fit as the wedge is only 3/16" at the bottom. With my wedges, I put some duct tape on the front side of the top holes, filled them with epoxy resin and drilled the holes in the right spot. I assume that wasn't necessary but I liked the idea better of having them locked into place.
Chances are good you will need to replace the top two bolts with ones that are 1" longer. The bottom bolts will probably still work (as long as you have some bolt sticking out still).
ghind, It is interesting to me that we live on opposite sides of the world, we will probably never meet face to face, and through a lot of trial and error we have come to many of the same conclusions concerning the technical aspects of outboard ski boats. I have found that you and I have similar ideas in areas like throttle linkage, props, engine height, the wedge, wake control, attitude toward additional weight and others. I don't drive at the nationals any more because my daughter retired from competition. On many occasions though I had people come up to me a say how good it felt to see an old restored 18 Dyne pulling in the individuals. It just made them feel good. I told them it made me feel good too. Incidentally my daughters 17.6 has a 300 pound motor on it and it runs a wedge. The result is that the boat will carry a lot of weight and still get on plane at low speed. He runs fully tucked at swivel ski speeds. jim
Jim, I don't post often as most of my questions are answered by reading previous posts like yours. First test run begins next week on my 17.6 with a 150 Optimax. I will try it as delivered from the factory. No wedge, no trim tab, no weight up front and the motor is mounted at its lowest position. I will be asking a lot from this boat. I need it for low speed work such as saucer acts to higher speed stuff like barefooting. Lots of work ahead. Boom has to mounted, different props to be tested and the throttle linkage/cable checked. Thanks to you guys I will have a better idea on what to look for and how to make the adjustments. A labour of love no doubt. Cheers, Kevin
Kevin When you level your boat on the trailer and trim the motor level, you need your cav plate to be above the height of the bottom of the boat. Otherwise you will get a bump and probably spray. 1/2 inch may be enough. What height is it at the moment. Hole is not important, position of the cav plate is what matters. Of interest on the topic of wedges is that Evinrude have built in an additional several degrees of negative trim (an inbuilt 3 degree wedge if you like) into all/almost all E-TECs. They brag about slow speed and level boat attitude due to light weight but the wedge effect would have a LOT more to do with it. You Opti guys may like to be aware of this as you can try that same effect yourselves with a wedge. Jim, my Dad was playing with this stuff 20-30 years ago and I can't help myself but continue. Nose tank, marine ply engine wedge etc. I really enjoy this site, would love there to be more posts, but what is here is quality and interesting so that is much more important. Serious outboard ski boats are pretty rare so I was delighted to find this site even exists. I'm about to go away for my last ski this weekend. This winter, I'll be swapping the Evinrude flush mount control for a Yamaha 6x0 (Due to my perfect pass setup I use standard 33c cables for my controls and the adaptors to make them Evinrude are sloppy). Would like to customize the control so my cables don't have to run forward and loop back (control box clearance left me no easy choice) and I'd also like to make it more granular at mid throttle positions. Too little movement makes too much difference for my liking. Not that important when you can just let Perfect Pass drive but I can make it better so I will. You guys have to try power assisted steering.... I also want to play with engine height and setback and props to optomize wakes. I've been very interested to read Jim's posts about cup, stern lift/sink etc. Anybody know what the Evinrude lightning gearbox wake is like compared to the magnum? There are two ways I can get a ride in a dyne. 1. Buy one and bring it over here. 2. Go over and see yours. I can't imagine what I would actually do with a dyne and a full on restoration is too much work for me plus freight is too expensive relative to value on a rough one. I would love a very good condition tripple. I'd get it out at least several times a year... How to afford it though....? Anyway, Jim I'm sure we'll meet cause the only way I'm going to get my ride in a dyne is to come over and see you guys! I'd love to see the show ski nationals, it seems like Dyne heaven. Surely somebody would take me for a ride there. I still get tingles every time I watch that video of the tripple threading the needle pulling four extra three tier pre built pyramids off the dock. Wow, that is driving skill and brilliant thinking. Must tell you guys about our local ski shows one day... Thanks for the great site Greg Hind
The Mercury digital throttle and shift is a very cool system and also expensive. It does eliminate the problems with cable routing. One of my neighbors does business with Mercury and had a whole set up before it was released for production. He had a prototype 496 in his Barefoot Nautique with the full Digital throttle and shift including all the smartcraft stuff and a doppler radar speedometer. I did a little work for him but I did not drive the boat because we could not get the exhaust set up correctly that day. The throttle operation was very smooth. jim
Kevin, My daughter's 17.6 had a 150 Evinrude on it for several years (with a wedge). That is the set up she won the nationals with in 2004. It took a slightly different prop than my 18 for some reason. It may just have been that two different shops built the two props. I use an un-cupped 17 and I had started with that on her 17.6 and had to have it re-pitched to an 18 to get the prop shaft rpm I was looking for. I never was able to get the wake as smooth as my 18 until we switched over to the 75hp with a stock 17 prop. I think she will tell you that she sees very little difference in the two wakes now at 16 mph. They were forced to down size to 75 hp when they got the lake place because of local rules. They don't barefoot, so it works fine. I think it would actually barefoot her, but probably not a big guy. I think your rig will do everything you mentioned with ease when it is properly set up. jim
Thanks for the insight Guys. I think the wedge is a forgone conclusion. Jim brought the idea of using a wedge and possibly raising the motor to my attention last fall. I figured if I had to raise the motor anyways, this would be a good time to have a wedge installed. Besides, if I don't try the boat without it, I will never discover what the changes are. As far as weight in the bow, I will experiment by moving spotters up to the open bow. Q. Does anyone use their trim gauge much? I never have. It always seemed I knew where the motor was trimmed by the feel of the boat and I'm always looking back at the skier(s) and motor anyways. Kevin
Kevin, Above about 20 I trim the boat so that the steering is neutral. The up and down trim affects the steering wheel loads. This is how I fine tune the trim requirements. This system will only work if the prop and engine height are in the ballpark. My daughters 17.6 has hydraulic steering so the steering loads are not noticeable. I do look at the gage as a reference. Sometimes I preset the trim if I am out playing and want the boat to stand up a little on take off. I use the trim gage for that. I generally use the mirror for setting the trim for beaching. So, I guess I use different things at different times. jim
