New Prostar Rudder Grinding Questions

[markchilcutt]

Lets say you have a brand new 2019 Prostar set to arrive in a few weeks and your thinking about getting this new whip dialed in.

1) Did you have to grind your rudder to get positive pressure on the steering wheel?

2) If you answered yes to question number one What was the process and how many times did you grind and test until you were happy with it?

 

Just asking for a friend.

Thanks

 

[keithh2oskier]

How does MC not offer a rudder tab? Nautique started doing that like 20 years ago...

[markchilcutt]

No tab.

[lakeho26]

After receiving my 2018 prostar a few months back I had the same question! asked around to MC promo guys(multiple) and experienced skiers and drivers with prostars ranging from 2015 to 2018. So far the only answered received was they have not had to do any grinding to there rudders. Weight was the only thing they said to figure out to make the boat level. Recommended to use two observers when driving a tournament with no extra weight. Curious to see what others here have to say

[The_MS]

@lakeho26 you are correct about the leveling. I would never get one without the ballast system.

I think @Chad_Scott has ground a few MC rudders so maybe he will see this and respond

[tru-jack]

the rudder on the new MC at our local dealer comes with a 'factory' grind. it is delivered by MC that way according to the salesman. looks like the photo @scotchipman posted

[DW]

Here is one:

[markchilcutt]

Thanks @scotchipman @tru-jack and the rest of you guys for taking the time! I will pass this information along to my friend.

[WoodySkier]

The prostar handles completely different with weight under the observer seat, or a passenger. I’d try that before you grind. I know guys are changing the attachment point on the rudder to make the steering more sensitive as well. Really crazy that they don’t just put an adjustable tab on the rudder, as others said Nautique has been doing that for 20 years.

[ScottScott]

I was asking the action guys at the orlando boat show about that. They showed me the new 2018 prostar they had at the show, it already had a grind from factory, my 2017 has it also (I'm 99% sure it was factory.)

[skibug]

We have a 2015. The rudder comes from the factory with material removed from the trailing edge of the rudder on the starboard side. They say this is supposed to be the optimum shape based on testing and "tournament" driver's input. I disagree. In fact, on ours it was too much and we wound up grinding the opposite side of the rudder to get rid of some of the rudder torque. We also moved the steering connection to the inside hole on the tiller arm of the rudder. This helped out in our situation and I know others have made this move as well. Also, weighting the boat is very, very important to get it to handle correctly. We did a lot of experimenting with weight to get it dialed in. One thing we realized is that weighting the boat to make it level needs to be done no further forward than the passenger seat; and in fact, it works better if you use bag weight on the floor, up against the gunnel (not under the seat). I think this has to do with the location of the tracking fins. If you look at where they are located versus the SN200, the MC fins are much further toward the stern. I have found that it handles best when there is just a slight list to the port side when setting still in the water.

[skimtb]

Best spot to get Weight bags?

[LLUSA]

I'd say I've got @Chad_Scott beat :) on grinding rudders over the years, first balance the boat, drive it, if you feel there isn't enough torque on your steering wheel, then in the same area MC has pre ground your rudder make 2-3 passes with a grinder, put the boat in the water, drive it, if it doesn't have the feel you want, pull it out and do it again. I've found that MC's are very sensitive to rudder shaving, you can easily over do it and there are ways to correct it but it's easier to take your time and get it right.

[Horton]

When I got my most recent ProStar I added some weight under the passenger seat and then added some weight in the bow. Best driving boat I have ever had.

 

Don't forget if you're pulling little kids or anybody skiing below like 26 miles an hour pull the bow weight back out.

[markchilcutt]

@Horton when you get a minute would you mind telling what you used for weight under the seat and bow and approx. how much in both areas. In my 14 we used passenger side weight if no observer was present but never added weight into the bow.

[The_MS]

Depending on driver weight you need at least 150lbs under seat.

[LeonL]

Those pictures posted by @scotchipman show "grinding" that was obviously NOT done in someone's backyard. That's too precision for hand grinding. Whatever year (I forget things) the newest version of the MC came out, those boats had way too much rudder torque, as @skibug stated.

[BraceMaker]

@LeonL that looks to be casted.

 

You can easily get that precision using a good file just clamp a scrap of wood to your rudder so it forms a reference plane for the file and go to town keeping the file just off the block. Adjust block forwards for a steeper pitch and back for shallower.

[Golfguy]

Im about to take delivery of the 2019 MC so: Is the MTS system adequate weight to balance the boat? I can understand the rational regarding the rudder tab. Not having an adjustable tab reduces the possibility that boats will drive differently depending on how the owner has set the tab. Thank you for any comments.

[coach3]

As the boat levels, torque is increased. The rudder comes with a slight torque steer. If you are by yourself driving it will need some weight to level it. I prefer more than stock, so a hand grinder to widen the relieved material on the starboard side of the trailing edge works well. Just take a little off.

[blagrata]

@Horton Do you keep the bow cover on plus add weight in the bow to keep the balance that you refer to? Do you find the bow cover integral to the appropriate balance of the boat above 26 mph?

[Andre]

Is it just me or i would really hate having to take the grinder to my spanking new 85k boat...

[swc5150]

@Andre It's a much scarier sounding proposition than actual practice. A couple of swipes down the port side with a flapper wheel will reduce the torque. From there it's all preference on much torque you want taken out. You can also add torque back in by hitting the starboard side. Takes some patience and a boat lift reduces the time involved, but there's really not much to it.

 

MC really should offer a tune-able rudder though.

[Andre]

@swc5150

Wouldn't be scare on my 94,but no way in hell should you have to do that to a 2019 boat...

Not sure of the % of owners that do it to their new MC.

[markchilcutt]

@Andre it all depends on how much rudder torque you want on your boat if any at all. Hell most walleys will never touch the rudder. If your pulling short line slalom skiers you want that load in order to give the best ride possible with the least amount of driver input.

prop change, rudder grind, check all the steering linkage, add weight to passenger side, map courses, install amp and sub and go skiing!

Thanks for all the input everyone.

[swc5150]

@markchilcutt New Prostar's come from the factory with a LOT of rudder torque. Overkill IMHO, but that's subjective.

 

@Andre That is a fact! Tunable rudder should be standard equipment as of 15 years ago. But filing the rudder is easy. You just want to shave a little at a time until it's dialed in to your liking.