I was going for my first WFO run last Friday. 

Had drives set to "5" and tabs at "2" ( I have the rubber bumpers that prevent raising up tabs past "2"). Water was almost glass, full fuel and just me in boat. At abt 76mph, I got into some serious chine walk.
Boat went from rub-rail to rub-rail 4 times in abt 1 sec. On the 4th oscillation it felt like the boat came out of the water and turned abt 20 degs to the right. :o

One of the experienced Fountain guys I know said to run the tabs at 3 at high speed. I haven't had a chance to try that yet.

I've read that you can prevent it by steering opposite of the oscillation (i.e. boat leans left, you steer right), basically balancing the boat on the pad. Not sure I can steer that fast accurately.

Anyone here experience chine walk at high speed?

If you can steer thru it, will it settle down after you reach a certain speed?

Will ext steering stop it or just dampen it some?

Remember when I suggested you add external steering to your short list? Your gimbles are whooped. Stand behind your boat and move drives side to side. That is where your problem is. If you try to drive through it with your steering the way it is you WILL get hurt.

I had always been told that trim and tabs can help.  you have to find the happy settings

To repair it properly you should repair the gimbles and add external steering. There is a dimension for the height of the gimble. As they loosen the fall. As a result u joints begin to operate in a somewhat kinked mode because the yoke in the coupler is no longer in line with the input to the drive. Once the gimbles are in there proper location add external steering.

With steering your boat will feel entirely different. It will track straight across chop and wakes. The boat will not wonder as it does now. Any chine walk that may develop at that point you can learn to balance and drive through.

Once you get external steering you will wonder how you ever owned your boat without it. It really adds a ton of confidence to your boat at speed and just feels so much more smooth.

Going thru the drive mounts was already on the list for winter projects. If I lift up on port drive I get a little bit of play. Starboard drive is tight.

I'll be replacing all the bushings when I dig into it.
Hopefully I can spring for the ext steering. May be a half and half sys for a while. We'll see.

Add a couple gimble rings, a swivel shaft and tiller arm or two to your list. The part that is causing the wonder and chine walk is the free swing side to side when you grab the outside tie  bar. It is primarily where the upper swivel shaft meets the ring.

You are lucky when it went 20 degrees to the right it didn't throw you on the floor or out of the boat.

Those pucks in the trim tabs restricting the up limit need to stay.

Add on steering will do what you need to.  Full hydraulic is nice but costs twice as much. The hole in the dash is different and you will likely end up replacing the dash panel too. Don't waste your time considering any steering stabilizers like side winders. Complete waste of money.

Be careful in the mean time.

I have add on steering on the Nordic (half) and it is great. Manners around the doc are better, at speed it is almost a set and forget type thing. And a big polished hydraulic arm on the back just looks good too.

I would take Jim's advice and leave ego at the coat check.
Here, you have suggestions from a man who has been working on Merc products for over 30yrs, rigged and drove Fountain's own race boats at the factory in the 90s and early 2000s, has obtained kilo-record speeds runs and a national championship in offshore racing.  He knows what he's talking about and anyone who thinks his words carry no merit is acting foolish.  Your life is in your hands at boat speeds of 70+mph and it's just common sense to let a professional tackle a repair like this.  I'm a decent mechanic and do most of my maintenance and repairs myself.  However, I can tell you that these repairs are not a job for the average guy and there are numerous specialized tools from Merc that are needed to do it right.  When he says both of your gimbles are done, I would take that with a grain of salt, get them fixed and fixed right before something bad happens. 

One a second note; running fast on glass water is a recipe for disaster in the smaller Fountains. Most likely, boats from other manufacturers as well.  Mine chine walks above 70 too and once it gets out of shape I'm merely a passenger at that point.
I've found there are two options when this happens:
1. it will settle down enough for you to get it back under control. 
2.  it won't and something bad is about to happen.
I've learned not to run it that fast when conditions are flat. The more chop under the boat the better it will handle and as Jim said, you can learn to drive through it. I've found myself deep in #1 a couple times and don't EVER want to be there again. I got lucky, plain and simple.  I've spent quite a few hours on a boat with Jim and he's taught me more than I would ever have learned on my own.  His advice is immeasurable.  There is so much more to driving fast boats than pushing the sticks forward and trimming them up. 

JC - I don't know you or your background but noticed you have come on ABF and OSO asking for advice several times only to have already made your mind up on the topics you seek advice on.  In my opinion....and it's just that, an opinion, I would pay a bit more attention to the folks who are offering the advice.  I'm a know-it-all myself and over the years have learned that most of these folks know what they're talking about.  If your 29 is your first performance boat and you intend to run it like it should be, I would open up a little to these words of wisdom.  I've done it myself and can tell you that it has paid off in spades more than I probably realize.

Evan - this goes for you, too.  I know you want to go faster and have Bob working on some things to make that happen.  Be safe! 

All I can offer both of you, and anyone else for that matter, is advice from my own personal experiences.  I've been boating since I was 6yrs old and thought I was a good driver and captain.  I thought I was king-shit when I got my first, fast boat.  Consequently, I crashed it 2wks after I bought it because I was being stupid.  I don't wish that experience on anyone and certainly don't want to see anyone get hurt.  Whether I know you, or not.  I can also tell you that boater safety courses and general rules-of-the-road instruction can be invaluable. Especially, on these small lakes when there are so many others who shouldn't even be allowed to step on a boat let alone pilot one.  Going fast takes experience and carries responsibility.  If you blink, something bad can happen.

I apologize for the long reply and if anyone is offended by my words.  I want everyone to boat smart and boat safe.

Griswald I believe that you are coming on this forum with a uninformed opinion.  I too have been boating since I was six and even though I have never owned a "fast" boat I have had several and never crashed a boat.  I recommended this forum to Jim when we were both on Austin bass fishing.  I also have meet Evan several times and been around here for a while.  I know that Evan listens to people when they give him suggestions especially when it comes to someone of jims caliber.  As for JC he seems a lot like me.  I will listen to everyone's option and in the end it depends on what I can afford to do.  I would not have the funds to add the external steering to a boat so I would have to look for a less costly upgrade.  I believe that you are off base on your "opinion".  I did not read in any of JC's post that he was not going to look into what Jim said.   

I respect your reply Nathan but disagree with your comment.  Please re-read my post and note my humility expressed no less than three times.  You have previously posted that you would never operate a boat at more than 50mph so I don't really understand why you have a comment on a thread about chine walk, what could be causing it and what repairs it takes to help mitigate.  I will not get into a pissing match on the interweb.  I've also learned over the years that is an exercise in futility.  You folks have a good day and safe boating to you all.

My comments come from research and talking to people that own the boats.  I have been on fast boats and Have piloted them at speeds above 60 mph.  I have said that I would not own one because my family would never go on one.  my wife and daughters do not like speed on the water.

my comment come from your direct call out of JC and Evan like you know exactly how they think or operate.  I would say ask the people first before you call them out on a public forum.   

Hope all have a Great weekend and rest of your season.  JC good luck on your impending repairs.  Evan I hope your sunny is back together soon and problem free.  Jim Thank you for all the advise you give from our vast knowledge.  Griswald thank you for your knowledge as well.  happy boating Nathan!

Nathan, I remember you made me aware of this site. I would like to share a few thoughts. Boats that go 50 or 60 mph or more are a completely different than boats that don't. That misconception, that a lifetime of boating experience means anything when you start going fast DOES hurt and kill numerous people every year. Just this weekend there was another tragedy. Two people were killed  from operator error. IMO most people buy boats they have no idea how to operate properly. I was in the same boat in 1984 when I crashed my first fast boat. I have learned many hard lessons over the years.

I am not hear to argue or sell work. At first I offered assistance by answering questions. I do very little of that anymore. Lessons learned on the internet are just hear say.  I find few opinions carry any merit. In this case I spoke up because IMO a life or death subject was opened.

I am not passing judgement on JC. We have only briefly met when he asked my to look at the Fountain he bought. I can say I agree with Clark and his interpretation of his questions. I agree because I experienced the same. His mind was made up he was buying the boat and didn't care what comments I had about it. He only wanted me to look at one aspect of the boat. I pointed out the steering and he disregarded it as irrelevant. 

I was easy on him in my last post. From what he described and the question he asked he had NO idea he was a whisper away from spinning it out, ripping the drives off the back and sinking the boat. I had to speak up. Had some " experienced operator" share some baseless info and he tried it again and got hurt or worse I would feel bad about not speaking up.   

I could go on and on a number of different directions here but let me share just one of my 'Hard lessons". In 1994, I share the date because it was 20 years ago and I have never been hurt so bad in a boat. I raced a 63 MPH boat like I could not get hurt. It was not a matter of ability. It was a matter of ignorance.

I had been much faster, had spent many hours going faster and refused to even acknowledge I could get hurt at 60 mph. We were leading the race and before I could blink, flinch or say WTF it was over. My buddy was in the water. Nothing new. The deck was loose on the boat down the entire starboard side, again nothing new. The seat I was sitting in was torn from the floor. No big deal.

When I left the emergency room I had 9 broken ribs. There was a different incident on the race course that day and he wasn't as lucky. I could just as easily passed away that day.

DON'T think for a minute 50 or 60 miles an hour is a safe speed. Its not. Water is unforgiving and it can get you with the boat stopped.

I don't care what argument or justification anybody might have on the subject of steering. It is a critical function and should bee addressed accordingly.

If  you chose to dismiss this post I don't care. I have said my piece.

I agree that there is truly no safe speed on a boat.  Please do not stop giving advise or stories.  That is the one of the reasons that I told you about the site so you could be here and tell us about your boats.  The person that ask the question may not take your advise But I can insure you that I and others listen and take your advise and keep them for my build.  I will be building my 23' chaparral and looking incite like yours, griswalds, and any other people that have worked on boats.  the biggest boat I have owned is 18 foot so this will be a new level for me.  I just did not agree with calling people out.  if they do not want to listen to the advise someone will and it is their loss.         

I get into chinewalk on smooth water, light on fuel,  WOT (68), no tabs, trim at 5.  Mine is very slight, but there, I know I have pushed it to the max.  Throttle comes back ever so slightly and trim goes back to 3.5 where it likes to be, high speed run alone, over now, back to cruise mode.  My next major upgrade is the steering, that will top off the FAS³Tech with what it should have come with standard.  Be safe out there everybody.  Thanks Jim your reads / posts are very informative.

Wow! This discussion turned ugly quick.

First off: I believe everything Jim tells me abt boats. I have no reason not to.
I did have him check the transom and stringers of the Fountain. That's an area I don't feel confident repairing myself.

As far buying the boat no matter what Jim said, that's not correct. If that was the case, I wouldn't have asked him to check it out to begin with. If he had found anything questionable with the structure I would have walked away. He said it looked good so I proceeded with the purchase. I figured anything else that came up I could handle myself.

I've been turning wrenches for 30+ years professionally. I do know a thing or two abt mechanical things.

I do remember Jim pointing out the port drive was loose where the trim cyls attach near transom. That was rectified within 5 mins of him mentioning it. I don't remember him checking the drives for side-to-side slop or him mentioning he found excessive side-to-side slop.

He did discuss ext steering with the prev owner while I was there. The prev owner said he discussed ext steering with Reggie when he bought the boat. They agreed the extra 75 lbs on the transom (on an already tail heavy boat) would do more harm than good for handling.

I feel with the added HP the boat has now, ext steering is a great idea. Its just a matter of time and money.

Griswald: I think your intentions are good, but I also believe you're taking things a bit too far too soon.
I do tend to think outside the box at times, that's who I am. If you knew me, I think you would realize that after exploring all the possibilities, the final decisions I make are usually in agreement with what the more experienced people suggest.

Any slop I find while I'm removing the drives will be repaired. It's as simple as that. I don't allow ego to override anything safety related. That's just plain stupid.

Good to hear JC!!  Keep on boating!

I am not convinced you understand where the slop I am referring to is. I did not notice your pivots and bushings to be worn. I am specifically referring to the looseness in the steering. Move the drives left and right with your hand on the tie bar as if your were turning them with the steering wheel. That is the dangerous part. Understand for ever increment the drive swings free the boat wonders some exponential amount more side to side as it chine walks. The drives have a tremendous mechanical advantage working against the tiller arm. Think in terms of distance of the tiller arm and propeller from the steering axis. The tiller arm is about 5 inches long and the propeller is about 6 times greater a distance out the opposite direction.  The outside steering nearly matches that distance on the same side. Simply the boat working the long side of the see saw and the steering is trying to fight back from the opposite  very short side.

I call BS on the weight to benefit notion. It was a money thing then as it is now.

My persistence on this matter is all about your safety. Please understand its your well being at stake. Do not think for a minute you have control over your boat at speed and please do not listen to anyone that says it is ok or that you can trim it different and drive through it. I don't know how to explain it any better.


Best wishes.

Griswald wrote on Sep 8^th, 2013 at 9:25am:

Evan - this goes for you, too.  I know you want to go faster and have Bob working on some things to make that happen.  Be safe!

Definitely priority number one. If there's any free advice out there on doing something differently I'd love to hear it. Advice is cheaper than broken parts or worse.

Jim, in regards to wear causing steering slop, I believe you're referring to the gimble ring to upper shaft fitment and the upper shaft to lever arm fitment.

Are the drives supposed to be tied together inside the boat if ext steering is installed? I've heard yes and no.

If no, then seems like I could save some $$ on gimble ring, shaft and lever arm and put it  towards the ext steering.

Yes that is the slop I have been talking about.

Regarding tie bars. There are different opinions available. Here is the thing. Whether you have standard, add on, or full hydraulic the outside tie bar is the main one. An inside bar is not necessary. If one chooses to use an inside bar there needs to be a slot in one tiller arm pivot. The reason is two tie bars create a geometric bind when the drives are anything but perfectly matched in trim movement. It is back to the distances the bars exist from the steering axis. If the drives are misaligned at any point[  and it is inevitable the will move different at some point ] all the pivot bushings get side loaded and the tiller arms get loaded and they all wear out prematurely.

On the gimble rings the deciding factor as to if the need to be repaired or replaced is first the height the are. It is measured and the lower vertical pivot. I believe the spec is .001 to .025. Excess off .025 can cause a vibration, wear out the coupler and u joints and even damage the drive.  Gimbles tend to drop for a couple reasons. First the steering slop accelerates wear specifically where the ring hangs on the upper swivel shaft,  second general use, and finally corrosion. The steel shaft against aluminum. I paint that joint with perfect seal when ever I assemble new parts. Understand  that joint carries allow the weight everything that turns. The ring bell housing and drive.

The reality is the gimbles need to be right, add on steering does not make up for worn parts and two tie bars will ruin new parts. I find the experts that race sites that know better or are misinformed and add two tie bars are the same guys breaking bell housings and stripping out hinge pins

Finally understand the tiller and gimble need to be right for add on steering. The system operates off the reference the tiller arm provides. Loose tiller arm causes the hydraulics to shutter.

If you choose to confirm this info there are only two people to ask Latham or IMCO

I would also like to mention you should see what generation bell housings you have. Early Bravo had hinge pins screwing into the bellhousing. A washer was added sometime around '90. You can see the two offered on parts break downs. You want the ones with washers. The pin bottoms against the washer and it effectively holds the pin on its axis and they last much longer then those with out.

Nathan like stories here is one about this subject. In '90 a friend of mine had a '88 30 Velocity. That boat ate gimbles. 3 sets in one year.

to be continued later...

you have my attention.

OK Nathan, I am taking a break in front of a fan. Before I start that story I want to provide a little back ground. My first shop was at my friends Marina where many of the Velocitys he sold were dry stacked. It was on the end of the Severn River off the Chesapeake. I had run countless 22's with 260's, 454 Magnums, [ 330 and Alphas  ] 320 efi's, some with 200's and he raced one with twin 200's. The 30's had a number of power options too. I had spent many hours in one with warmed up 400 and #2 speed masters, My buddy Ronnie bought a new 30 with 330's and TRS. He took delivery in Florida drove it home to Annapolis from FLorida. He had 125 hrs on it the first month. When I winterized it the first year it had 325 hours on it. He ran it everywhere wide open. It was often painful to be a passenger cause he leaver let off. At 700 hours I forget when exactly he broke a crank and it was covered under warranty. A 30 is still one of the funnest boats I have ever spent time in.

Now Greg and Jeff bought there boat the Red 1988 30 new. It was the third boat they owned that I took care of. After the first to years they had pretty much run it until it stopped and it was in need of numerous repairs. Greg and I had become close friends and the summer of '90 he worked for me. We had come to an agreement I would fix everything on his boat with his help, He and his brother would pay for all materials, The three of us would split the lift slip cost and I could use it like my own.

Let me say in 1990 gas was 140 a gallon at the marina and the boat held 150 gallons. We went out every weekend. Gregs procedure was to invite his friends usually 6 plus the two of us, we had even perfected a formation in the cockpit to carry 10. A typical Saturday morning would be me delivering the boats of the week while Greg prepped the boat and met his friends at the gas dock. Each person had to have money to pitch in for fuel every stop. 20 each would usually fill the boat. I would show up and we would

Leave. We would run 8 miles out the river and about an hour in any number of directions up or down the bay. Greg would drive all day I would be the night time Navigator. If the boat was on plane it was running 4500, his cruise speed. it would turn 5000 with 25 Mirages at 70. He would run it so hard and long that when we stopped and some one had to pee they discovered the drives were to hot to stand on. We literally ran it so hard it would wear the belts out. Most days we would fill it up 3 times. First in the morning, again late after noon and again at a friends restaurant were I was allowed to pump my own gas until the restaurant closed around 11 pm. Most Saturdays would end with last call down town and a 20 mile ride home to the slip.

Sunday Morning would start the same. Red Eyes Dock bar had a Bikini contest every Sunday. We would go straight there 55 miles away get fuel and assume our spot nest to the stage. When the contest was over around 3 we would press on.

We never did get around to fixing the gas gauge or bilge pump. The pump was out of reach under the engine and was beatin to pieces long before. Never ran out of gas. The boat went to OC MD and Point Pleasant NJ that year. Each has its own story. No hour meter but I would guess it saw 3 or 500 hours that summer.

To date still one of my most treasured times.

Back to the rings. I learned a lot about gimbles, hinge pins and tie bars that year. I learned it all first hand. One had already failed and was fixed under warranty the year before. That time the drive came off it ended up on the trim tab held on by trim hoses and indicator cables. The first round the summer of '90 We drilled the access holes and tightened the gimbles and steering arms. The hinge pins were loose and the holes wobbled some. We bushed the rings. Heli coiled one of the threads in the bell housing and loctited it all back together. That lasted about 2 or 3 weekends. The next round it got new bellhousing and 1 ring. At that time I realized the tie bars may be contributing to the problem. The indicater cables were changed and fine adjusted and  Removed the inner tie bar.  That lasted a month or so until when I spun it out thru my friend Jay out of the boat. That broke both of the new bellhousings and both gimble rings. I was lucky they stayed on the boat. Had to idle back over an hour.  The parts were on National back order. We found parts after a day on the phone and had them shipped in next day from all over the country. The boat never missed a weekend. Luckily nobody got seriously hurt.

Some time early 90's mercury upgraded the bellhousings and added the washers I mentioned. They also eventually added the HP transom to the line up with the ssm style hinge pins. They are pretty tough. The still will break if the boat is spun out.

Since then I have serviced countess gimble rings included Griwswalds a few seasons ago.

It is my opinion any boat faster then 70 MUST have external steering. Most boats now comes with external steering standard.

I sent my entire outside steering back to Latham to be reconditioned, re chromed, new plates and re fit with new clevises. I now have no rod ends. I will be sporting a new tie bar too. Nearly 3000 dollars later.

that is the kind of summer weekend I dream of. great story

Jim; Thx for the info on the gimble ring specs. I didn't think abt the ext steering needing  feedback. Are the gimble rings, upper shaft and lever arm normally replaced as a set?

What are your thoughts abt cutting out a section of the gimble housing out to access the nut on the upper shaft? My first impression is not to do it, but looks like a lot of guys do. Pulling the eng and transom plate appears to be the only other way.

I checked the side-to-side play today and looks like I have abt 1" of slop measured at the prop.
I assume the slop can be checked with power steering sys depressurized.

BTW, great story. I enjoy reading those too.

The access kit from merc is 22-88847a1 It is a hole your thread and install the supplied plugs. My preference is that over the plate type some one makes. The plate does allow easier access but IMO is much uglier. Either way cutting or drilling sucks. I have some chisels I have modified to make it easier to move the nut. Yes I agree pulling engines are not practical for this repair. The first time It took Greg and I all day to do both sides. Once the plugs are there it can be done in half the time.

In salt yes. The ring is the expensive part the shaft will only need replacement if corroded. The tiller is steel too and may be ok. If time is not an issue remove and see.

It doesn't matter about pressure on. You are checking all the lash from the inside cylinder back. If you look carefully you can probably watch the ring move on the shaft from the back of the boat while looking up at the bottom of the shaft. Measure the bottom pivot to see how much the have dropped. Look to see if the the upper shaft seal has fallen into view and you may be able to better predict what is needed. I remember the drives swinging freer then 1 inch but it really doesn't matter I know they they swing more then is safe enough to make it unmanageable  to speed.

Great post.  Thanks for all of the info and great stories.