Jim, What engine rpm do you pull swivel at? you run a 17 aluminum prop if I remember right. Rigged a new 150 E-Tec last night and ran it, does not like a certain spot around 22 rpm with a 17 pitch ss. Going to try the 15 this weekend.
Has any body ever tried using a smaller (either narrower or shorter) ski for swivel so the boat can go closer to a normal planing speed? Just a thought. If I remember correctly, our twin with 17 pitch stainless runs around 2100-2400 for snivel ski speed (depending on the skier).
I use a 17 aluminum that has the cup removed and it spins like a 15 but with less turbulence. At 16 I am turning about 2750. I took my grandson all the way around the lake on his knee board at 13. Before I had the cup removed I think it turned about 2400. My daughters boat had the same prop, but I had to repitch it to an 18 to get the propshaft rpm I wanted. A smaller ski will produce more speed and that is bad. It cuts down the time of each pass and limits the number of moves the skier can perform. It looks bad too. The boat should be tailored to the skier, not the reverse in my opinion. This issue is why when someone tells me they can pull swivel with a 21 I don't believe it. A 19 will have the motor turning so slow that there is no speed control. jim
I was just looking for a reaction with that comment. There are times that it would be nice to have them able to go a bit faster though. Like in a 4+ boat pattern with multiple types of skiing in the same act.
I know those acts are popular. And I also know that swivelers are not very well accepted in some clubs. Don't expect much out of the swivel skier in that type of mix, even a champion. They need exact speed and calm water to put on a proper performance. Some clubs are just not interested in that. jim
As long as we're off topic, might as well continue. I wouldn't say that swivel isn't accepted in some clubs. I think the majority of it is just friendly banter between teamates. If you are a strong show team, you have to realize that snivel is a part of the show, and as much as I hate to admit it, is a key component in a well rounded ski show. On the multi discipline acts (sometimes called a "flurry" act), the best way of doing it is to have all of your boats start at the same end and do a single pass through the show show course. This of course, works best when you have a lot of boats. It's tough to get a good act with only 2-3 passes through the show course, unless you are doing the one boat show (pyramid, jump, and barefoot behind the same boat).
To get back on subject, my engine has a low rpm that it does not like also. I had hoped that the dfi engines had eliminated that. It must be in the porting. It is probably the bottom of the power band. jim
It is actually where the fuel injection changes from stratified (lean low rpm) burn to homogenous. I've been told this transition point can be changed by software update, but we'll see.
Don't you think it is just the makeup of the 2-stroke motor? They like alot of rpm they always have. I'm certain with the onboard computers and DFI that the outboards now use helps. The 4-strokes can run all day at 1900 rpm. As a team I wish we had more dads like you Jim that would spend the time to help figure stuff like this out. Unfortunately we don't and showteams can't tailor a boat for one skier or one act for that matter when you pull eight different acts with the same boat. I am sure that we have lost quality skiers for that very reason.
