Exhaust leak

[junaido]

Last weekend, coming back from a sail, I noticed the cabin was very smoky. Shut engine off and sailed to a nearby dock. Closer examination revealed water gushing from the nipple/exhaust riser area. I was able to limp back to my slip, which was pretty close. Engine temp stayed normal. Here is a video of what is going on.
https://youtube.com/shorts/UnRdK4REvL8?si=ymg-kRBSAhbFxa7k
Any suggestions on how to approach this problem? I am guessing I need to pull the exhaust off and either get a new one from Catalina Direct, or make one myself, but could there be an easier fix? I did recently change the HX zinc, and this was the first time I took the boat out after that change, not sure if that had anything to do with it. This is a '86 C34, M25 engine.

Thanks,
Junaid

[Stu Jackson]

It does appear your nipple failed.

Here are some Tips & Tricks for riser replacement; the article also notes previous replacement tech notes.


February 2016 Vol 34 #1

    Muffler & Exhaust Riser Replacement    (HTML) (PDF)

https://c34.org/muffler-exhaust-riser-replacement-2015/

[KWKloeber]

No changing the anode has noting to do with the exhaust riser.

It likely failed at the water injection nipple due to heat, acid in the exhaust, and corrosion.
Get it unwrapped and inspect to see the exact situation/condition.

Your choices are stainless one piece, black iron pipe/elbows, or stainless pipe/elbows.  Do not use galvanized.

If you don't already, when you replace the riser install a silicone hump hose.

[Ron Hill]

Junaid : The nipple weld that hold it on to the riser has fail - big time!!  The cause is probably the STIFF wire reinforced hose from the anti syphon valve had transmitted all of the engine vibrations to that nipple and cause the weld to fail. Replace that hose with a 5/8" nylon reinforced hose - which is flexibly!!

Your boat originally came with a black pipe riser .  You need to remove the riser.  If it is a stainless riser you MIGHT? be able to have the nipple rewelded IF the riser is in good condition???  Remove the insolation and inspect the riser.!!

A few thoughts

. 

[junaido]

I did unwrap some of the white insulation. Looks like there is a hole right above the welded nipple "Y" junction. When I try to move the smaller hose off the nipple the whole thing moves. Rest of the pipe leading from the exhaust flange has rust, but seems intact. Getting the hoses off is proving a lot harder than I thought. The diesel filter and the sink hoses are not helping. Is there some trick to getting the hoses off? The bottom nut on the exhaust  flange is also very hard to access and it's not budging despite PB Blaster. The upper two nuts responded well to PB Blaster. I am beginning to think it might be time to get a mechanic ...

[Stu Jackson]

The bottom nut on the exhaust  flange is also very hard to access and it's not budging despite PB Blaster.

Did you read the link in my reply #1?

[junaido]

I did read the article. Sounds like it's a 2 person job. As far as I can tell, one person holds a wrench on the bottom nut. The wrench is on the port side, and then second person tries to budge the wrench with a downward hammer blow / 2nd wrench . Does that sound right? Also I have only 12 point box wrenches, is that going to be a problem?

[Noah]

You need to soak all with Kroil oil or similar for DAYS, first. Then possibly use some heat.

[waughoo]

Might be worth looking into an induction bolt heater.  Harbor freight sells a budget version.  This would likely work better than a torch.

[Noah]

Alex: is this the type of tool you were thinking of. Looks like it would be pretty handy.

[waughoo]

Exactly the one.  The benefit is that it heats the bolt and not everything around it.  This is both safer and more effective for removing the bolts without breaking them.

[Stu Jackson]

I did read the article. Sounds like it's a 2 person job. As far as I can tell, one person holds a wrench on the bottom nut. The wrench is on the port side, and then second person tries to budge the wrench with a downward hammer blow / 2nd wrench . Does that sound right? Also I have only 12 point box wrenches, is that going to be a problem?

I think you understand it quite well.  It worked for me.  IIRC mine was 12 point, too, but if you're concerned it wouldn't cost too much to get one 6 point for just this job, it'd be worth the small expense.

[Ron Hill]

juni: Get the bolt heater and get the 6pt socket. The 12pt sockets guarantee that with a tough bolt you WILL round the edges!!   

A thought

[junaido]

I don't see any induction heater bolt-buster gizmos for less than $170 online. Local Harbor Freight people have no idea what an induction heater is, and they don't carry it. Six point offset box wrenches are also pretty rare, based on my visits to several local hardware/automotive stores. Is there any reason why a heat gun should not be used on the exhaust flange nut?

[Noah]

If you can't find an induction bolt heater, you could always try this technique.
https://youtu.be/ywaTX-nLm6Y?si=eRW1QR7Ci3c1eYxV