Rudder Filing

[chautauquasun]

Anybody have experience with filing a rudder. I installed a brand new rudder and rudder assembly, steering cable and helm. It steers like a dream until I hit WOT and as I get up around 35 mph the boat has a mind of its own...the rudder starts to dance...normally it pulls hard to the left at first then will start to kind of fish tail. I tightend everything up thinking the assembly was loose. It helped somewhat but didnt correct the problem. I called Jim Jackson from Viper where I got the rudder from and said most likely I need to file the back edge of the rudder to create resistance on the rudder so that it doesnt move from the slight slack in the steering cable.

I had never heard of this...but he said almost all of the new inboards go through this process and he has to do it to really dial in the steering. So he described that I need to file the back edge an kind of put a bevel on it. Not exactly sure what I am doing here...anyone have any experience with this....this is the first time i have ever heard of this. I trust that Jim knows what he is talking about....but I am leary to start grinding on my brand new rudder. Can anybody give me some more guidance on this?

Hope everyone is having a great summer out there on their Supras. Mine has had some minor issues with the carb...but I have to say we are having a ball with it this year.

Hope all is well.

Dan

[riveredge]

A little bit at a time! But yeah, like Jim said, take a file or something to the trailing edge and take a little off the whole edge, top to bottom. I wouldn't take more than a 1/16th at a time, and maybe a bevel going back toward the front of the rudder 1/2" or so, does that make sense? Then water test... etc

[87SunSportMikeyD]

Something about that doesnt sound quite right to me... I'm no inboard veteran, but you usually file the rudder to compensate for a steady pull in the direction of the prop rotation. This sounds to me like either an issue with the cable or maybe it needs grease?? Not too sure about the solution unfortunatly...

[mapleleaf]

I haven't done this myself but have read about it being necessary on Correct cRAFT REBUILD'S/ with rudder replacement. Jim may be hard to get a hold of sometimes, but when you get him I'd say his knowledge is very valuable.....

[Supra-in-steamboat]

I'm with Mikey on this one... Our rudders are offset for this reason. While I am not doubting the expertise of anyone, I can't help but be skeptical.
While rudder filing is practiced, adding a tab on the rudder (like they do on big boats- most over 25 ft) would be an eaiser fix. The concept is file right- go right, file left - go left.
Google some rudder file projects, you'll probably get alot of MC info as some of their newer boats track like doodie. You can file and test and repeat a ton from what I understand. (some even file underwater)
This post makes me think of high school physics class, Mr. Newton and Mr. Bernoulli in specific. Remember- for every action, there is an equal but opposite reaction.
Also 35mph seems to be a common speed for alot of boats... To modify a new replacement part to achieve a normal operating speed makes me think the part is wrong, or there is another issue. Good luck man.

[Supra-in-steamboat]

Forgot to ask. Have you gone over 30mph while viewing the cable assembly in the back? If it's all moving, the rudder isn't the problem.
Seller had to replace steering cable, helm before my purchase. Steering was stiff and at higher speeds it felt like "ghost" steering- not too cool. New cable, no problem. Check your cable again.

[Blackntan90]

Dan, I dont have a pic of mine, but it has been 'tuned' by the factory. I can see the why you are hesitant to do this- I would be too! Probably find someone local with expertise in setting up ski boats and check his references.

[rludtke]

Based upon the description, it sounds like the rudder is becoming unstable at high speed. In aircraft this is usually the result of excessive freeplay in the control linkage. I think the linkage and cable system should be dealt with before you file. Look for looseness in the linkage or cable. If your cable has stretched beyond what the adjustments can accomidate, it may need to be replaced.

[sybrmike]

Have you checked the "clamp block" that attaches the rear end of the cable to the bracket on top of the strut?

Towards the end of the last test drive of my Salt, the steering became very vague at high speed & then became very unresponsive at all speeds & turned into a very strong negotiating point for me. Luckily after I got her home, it turned out that it was just the clamp block had excessive wear & the pivot ball was about to let loose completely.

[mapleleaf]

Clamp Block...$88.00 from SKI dIM, really helped me out this year.....