Steering

[hparrett]

Hi;

My wife and I just purchased a used 2001 Sea-Doo Challenger 1800. It is in great shape. One owner and garaged. Only used on the Colorado River. We took it up to Lake Mohave to use it for the day and I found the steering to be a little difficult. When we give it throttle at around 2500 RPM, the boat wants to turn left very hard and I had to fight the wheel to the right to keep it going straight. This worries me for my wife who wants to tow the nieces, nephews and yes grandkids around. The couple that owned the boat put on an aftermarket hydraulic adjustable plate under the jet to lower the nose at speed. Does this hinder the performance or cause the steering issues?

Howard

 

[seadoosnipe]

Aftermarket plate?

Never heard of the aftermarket plate used for trimming the nose of the 1800. That boat has the Mercury V-6 jet drive and from all that I've worked with on this boat, they love it. No one has ever reported a steering problem.
If it's possible, take a picture and load it in your forum post so I can see how it's set up. It it interferes with the thrust off the nozzle, then yes, it probably is the cause of your steering problem.
Like I said, I've not heard of this device on the M2 jet drive boats, so I'm curious to see what this is and how it's set up.
The boat does like to stand on end a bit longer than a regular boat before planning out, but my opinion on that is, the boat is made for several to ride in it, so if you load a couple people up front, their weight will hold the bow down. The M-2 V6 engnine is pretty heavy.
But please, send me a pix so I can see it. And for your own information, if this plate rides any where equal to or just behind the nozzles thrust, then yes, it is certainly your problem.

 

[kustomkarl]

To add to seadoosnipe's comment, it could be possible that one of the nozzels is off angle and is out of sink with the other nozzle, causing it to pull to one side making it hard to drive stright.
Karl

 

[scarfie]

Snipe - here is the link to the trim system Howard is referring to. Think I may get one of these to smooth out the porposing and to cruise at lower speeds.

http://www.placediverter.com/index.php?page=mercury

 

[seadoosnipe]

Wow, well hello!....

Man, haven't seen you around for a while....How's things going? How's the Doo running? All problems solved? Or if it's like everything else, another one crops up after you fix one........:rofl:
Thanks for the link, I'll check it out.

 

[seadoosnipe]

Thanks for the link Scarfie.....and still good to see you hanging around. Thanks again for the link to Hparrett's obvious problem.
Although this unit looks and sounds like a great investment, you have to be deadly accurate in it's installation.
With the single engine M-2 series 1800, the horse power created with the Mercury engine is really high at the nozzle. With this trim plate, if one of the hydraulic cylinders has a bad seal or they aren't in sync with each other, then the plate will actually canter to one side or the other. I think this is causing your steering problem. With a canter to the left, the drag created left of the nozzle will cause your steering to pull hard to the left.
Scarfie has the M-2 powered 1800, I'm sure he can tell you that this boat steers well.
So if you've added this trim plate, that's the only thing that can be causing your problem.

EDIT:
I have looked at the site again and can't tell if the two hydraulic cylinders are linked to each other. If so, that would create equal pressure on each cylinder. But if one cylinder had a weak seal, the plate would still canter to one side.
This could also be hard to determine while just looking at it from the back, or maybe even measuring it because hydraulics deal with really high pressures.
Not knowing a lot about this, I do have a test in mind. If both hydraulic cylinders are exactly the same and interchangable, then take the one from the left and put it on the right and vice versa. Take the boat out for a spin. If it pulls in the opposite direction, then you'll know you have a weak cylinder. Also, hydraulics, like the brakes on your car, have got to be bleed of all air. You can check to see that you haven't got air in the system causing this to happen either.

And one more thing, then I promise, I'll shut up. Since it's only bolted to your jet pump, take off the reverse gate and remove the trim plate, plug your hydraulic lines and take it out for a spin. Yeah, it may porpoise, but you'd be able to check the steering system. You may find that you don't even need the trim plate..........O.K., I'm through.....tell me what you decide and how it works out!

 

[scarfie]

I've been lurking around here a little bit. I'm slammed busy with work and have been trying to get as much done with it while the weather is cold. I'm setting myself up to be outdoors in warmer weather.

Had a chance to crank up the Doo before the New Year. Unfortunately it didn't crank. Trickle charged the battery overnight and it started great. the boat is running like a top thanks to help from this forum. Now i have two things left to fix...the retractable ski pole is bent and no longer retracts. No big deal...I have that problem under control.

The other problem is a short somewhere between the ignition and the ignition contolled fuse block. Most of the time that block of fuses is shorted out and i have had to move running lights, bilge pump, blower, etc to the other fuse block which is now full. You'll probably see some posts from me when i start digging into this one.

Don't mean to hijack the thread. Sorry. I'm interested in knowing what Howard finds out about the trim unit affecting his steering. I was ready to buy one of these units but will wait to see what goes on in this thread.

Yes - my boat does steer very well (an M2 powered 2000 by the way). I did adjust the steering a tiny bit because it had a tendancy to pull left. The nozzle wasn't centering exactly.

Keep us posted on what you find out.

 

[seadoosnipe]

Cool!....

That's cool Scarfie......I think it's o.k. to add a bit of detail when the other member is dealing with the same boat and has interest in the same things. You both have the M-2, so your problems will be similar. Feel free to start another thread on your problem. In the meantime, I'll look at the manuals and look for continuity/resistance test that may help you localize your problem.
The trim tab. I did read up on this unit quite a bit and they do limit the amount of infomation as to how it's designed. If I were the owner/designer, I would too. I wouldn't want someone with a bit of mechanical skill to steal my design...:rofl:
I'm still sticking with the idea that because there are two hydraulic cylinders that excert such a high amount of force on that plate to trim out the boat, that one is either weak, not working correctly, or the plate is off centered to the center line of the boat.
I'm waiting to hear the reply so when can go from there. But, good to see you hangin around. I look forward to viewing your thread!......:cheers:

 

[hparrett]

Aftermarket trim plate

Hi to all;

Sorry it took so long for me to respond. I got really busy at work. I had my son take some pictures of the trim plate on my boat and I will attempt to attach them when I am thru with my comments. All of your comments make a lot of sense to me. I think the suggestion that I switch hydraulic cylinders and try the boat out is a great one. It will probably be another 2-4 wks until I can get back out to Katherine's landing but I will certainly do some testing and get back to you guys. I noticed that the two hydraulic cylinders appear to have adjusting nuts on them so if the cylinders are good and the lines are bled, then I might try some adjusting to see if that makes a difference. Looking at the nozzle from the back of the boat, I noticed that when I turn the steering wheel back and forth the nozzle does not appear to travel as much to the right as it does to the left. This might be an adjustment issue. Anyways, thanks a lot for all the comments. I will certainly get back to you with what I find out. The one thing that was very evident is that the trim plate works and drives the nose down.

Howard





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[seadoosnipe]

That's cool!

Oh man, do I know what it's like when things get busy. I had a little time on my hands so decided to rebuild both my Mikuni BN-40i carbs and after removing them, found 2 holes in my tuned exhaust and the water nipple leaving my head, going to the exhaust eat up with salt water corrosion. In my opinion, that one anode that Sea-Doo puts on my ride plate, isn't enough. I will be putting more on it when I'm through.
Now, I've got the exhaust welded and at the moment, in the process of putting on a new top plate to my pistons (one I had in storage from my spare parts collection).....wow, how good it is to be a dumpster diver for stuff like this.
Anyway, a job that turned out to be a day or so has ran into a week!....so, that being said, I know what your talking about.
If you have adjustment nuts on those cylinders, I'd do just like you said, I'd make small changes, say two complete revolutions at a time then test, till you can feel the pull getting better. I'd make no adjustments to your steering linkage to you make adjustments to your trim system. To me, it doesn't seem feasible that someone would just arbitrarily make changes to the steering cable without a reason.

 

[kustomkarl]

I would almost think that the manufactor of the trim plate would make the rams work off a single feed to keep them equal in pressure per side. If they have a equalizer valve, as I have seen in other applictions, check to see if the valves are working and not allowing one to have more pressure than the other. That trim plate seems like a great Idea. Don't forget to keep us posted on the results.

Karl

 

[seadoosnipe]

Me too!

Yeah, in hydraulic applications now days, that's what I woud think, but the pictures that I have seen so far, show two lines coming from the hull to the cylinders. May-be the equalizer is inside the boat, near the pump.
At any rate, he has determined that there are adjustment nuts on the rams so that he can change the yaw of the plate. I think this is where his problem lies...............

 

[seadoosnipe]

Closed....

After a month, I will assume that you've come to a successful conclusion to your query........
If you have any more problems, please feel free to open a new thread....:cheers: