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86 Mariner 3697 steering issue

Posted: October 14th, 2025, 5:00 pm
by MrMojoRisin
Hello,

new owner of a 1986 Carver Mariner that we purchased knowing we had several projects in store for us. Much cosmetic work freshening up the interior, but that is all on the wife's plate until she needs me. So i'm focusing on mechanical things for the time being.

Couple of issues that i need to get squared away... All electronics are MIA... i'm guessing the original owner pulled those before storage every year and the head units all went in a box that sold at the estate sale. Nothing newer was installed, and the 2nd owner managed to back it aground and bent the starboard rudder pretty good. No prop damage, and the rudder shaft appears to be straight with no leaks or cracks in the fiberglass around the rudder shaft. There is a decent gouge in the bulkhead(?) that the shaft runs through, but from i can tell it's not a crack as it doesn't go any deeper and doesn't show on the vertical face of the bulkhead. Couldn't get a great picture of that though. Both rudders still move freely, but the steering ram was (or is) damaged. I"m guessing that is from it hitting, but not 100% sure of that. I'm going to post some pictures if i can figure out how to add them.

Would love to hear anyone elses thoughts on what my best course of action would be. I ran out of time when I was up there so couldn't get down there to pull the cylinder off and the boat is a littel over 2hrs from home, so won't make it back up for a couple weeks.

The mechanic that is going to winterize it this week is going to take a look while he's there and let me know his thoughts. The boat is currently on blocks, on a blacktop parkign lot, so i can easliy drop the rudder shaft right now, but may try to get them to lift it up breifly so we can drop the rudder. I'm assuming a prop shop could heat it up and bend it back for me as a temporary fix.

Re: 86 Mariner 3697 steering issue

Posted: October 14th, 2025, 6:08 pm
by waybomb
The rudder can probably be straightened.
It will have to be removed.
Not sure if you can still get a piston for the hynautic steering cylinder. Or maybe you can find a rebuildable somewhere. Or maybe take the thing to a hydraulic shop. They may be able to piece something together.

Re: 86 Mariner 3697 steering issue

Posted: October 14th, 2025, 6:25 pm
by Viper
I can't tell how much room is below the rudder but you need quite a bit of height to drop it out. Hopefully they took that into consideration when blocking the boat.

Re: 86 Mariner 3697 steering issue

Posted: October 14th, 2025, 7:51 pm
by bud37
Welcome to the forum......be sure to inspect that area around the rudder support closely to be sure there is no glass damage from the force that bent the rudder.

Re: 86 Mariner 3697 steering issue

Posted: October 14th, 2025, 7:55 pm
by km1125
When you're putting it back together, remember there's an alignment to the tie bar. The rudders aren't perfectly parallel, there's some 'toe-in' to them. I have the specs for a 3607 and I'd bet yours would be similar if not exactly the same.

Re: 86 Mariner 3697 steering issue

Posted: October 14th, 2025, 8:42 pm
by MrMojoRisin
km1125 wrote:Source of the post When you're putting it back together, remember there's an alignment to the tie bar. The rudders aren't perfectly parallel, there's some 'toe-in' to them. I have the specs for a 3607 and I'd bet yours would be similar if not exactly the same.


That’s good info… where would I find those specs for my boat.. I didn’t see them on my first look through the owners manual. Any info would be greatly appreciated.

Re: 86 Mariner 3697 steering issue

Posted: October 15th, 2025, 1:40 pm
by km1125
MrMojoRisin wrote:Source of the post
That’s good info… where would I find those specs for my boat.. I didn’t see them on my first look through the owners manual. Any info would be greatly appreciated.


Mine was in the owner's manual. I'll dig it up and post it in this thread when I get a chance.

Re: 86 Mariner 3697 steering issue

Posted: October 22nd, 2025, 9:14 pm
by MrMojoRisin
km1125 wrote:Source of the post
MrMojoRisin wrote:Source of the post
That’s good info… where would I find those specs for my boat.. I didn’t see them on my first look through the owners manual. Any info would be greatly appreciated.


Mine was in the owner's manual. I'll dig it up and post it in this thread when I get a chance.


I did find the specs for the rudder alignment in my owners manual. That should help me once I start putting things back together. Thanks for pointing that out.

Re: 86 Mariner 3697 steering issue

Posted: October 23rd, 2025, 7:19 am
by g36
Welcome aboard

Re: 86 Mariner 3697 steering issue

Posted: October 27th, 2025, 4:40 pm
by MrMojoRisin
I made it up to the boat this weekend, to pull some things and get measurements, etc. While i was there, i checked and the steering system is still pressurized and the cylinder moves with the ships wheel as expected. If it was still attached, i would have steering. It appears that the extension tube broke off right at the threads going into the end of the cylinder.

Hynautic k-19 diagram.jpg

IMG_2131.jpg

IMG_2130.jpg


I’m guessing that is not reparable and I’ll need a replacement cylinder? I found a used cylinder on ebay for around $300 that looks to be in good condition. Or, SeaStar makes an aftermarket replacement that I can get new for around $ 650.

Any opinions on 40 year old used vs new aftermarket?