Mainship Waterlock muffler

[Sovereign]

Hi Mainship owners, I am trying to source a waterlock muffler for my 2000, 39’ . Having the engine reinstalled May 2/22 after having a full engine rebuild over this winter due to hydro lock. Trying to alleviate this ever happening again. The exhaust hose from the turbo charger is a 6” diameter, Any recommendations?

 

[Comodave]

Welcome aboard. I would consult with the engine manufacturer and see what they recommend for the exhaust system design.

 

[DavidM]

Centek and Vernalift make exhaust components.

David

 

[Gotwex]

Might want to look into this
https://www.fisheriessupply.com/centek-check-valves

 

[jleonard]

The key to preventing hydrolock is to first have the exhaust riser/wet elbow be as high above the waterline as possible in the boat. That means a custom-made unit.
Many of that era 390s suffered hydrolock from a poor exhaust design.

 

[Keysdisease]

I believe that on the 390 single engine versions Mainship counted on a drain in the lift muffler to stop hydrolock. This drain was tapped into the lift muffler near the top of the unit and above the waterline. The concept being that water in the unit that rose above the waterline would drain overboard before climbing up towards the riser and creating hydrolock.

As mentioned, a proper riser will significantly reduce this problem, exhaust flappers at the transom can also bring a degree of protection.

The difficulty is that the engine and exhaust are low in the vessel and the waterline difficult to get above while staying below the deck.

Centek is the largest supplier of these mufflers

https://centekmarine.com/product/category/propulsion-exhaust/

 

[jbbmillar]

2.5 quart paint bucket

Hydro lock happened to me twice. First time was nearly catastrophic with water in every cylinder and the oil. Got to it quickly and avoided an overhaul. Second time minor, just had to pull the injectors.

Solved the problem with a 2 1/2 quart plastic paint bucket. I just pop it into the exhaust anytime we aren’t in a slip. Cary extras in case it gets knocked out by a dingy or I forget to pull it before starting.

Very economical solution.

 

[Keysdisease]

Indeed, many find a fender sized correctly works well, and has a place to attach a line as well

Solved the problem with a 2 1/2 quart plastic paint bucket. I just pop it into the exhaust anytime we aren’t in a slip. Cary extras in case it gets knocked out by a dingy or I forget to pull it before starting.
Very economical solution.

 

[Sovereign]

Thank you all for your recommendations, I am in Toronto and am scheduled to launch on May 5/22, I am thinking I had better postpone until I have this exhaust issue resolved. I just had the rebuilt Caterpillar engine reinstalled yesterday, I have been working with suppliers of flexible exhaust hoses so that the hose has a least a few bends in it. I have also seen stainless steel exhaust flappers that appear to provide a better barrier to sea/lake water from pushing into the engine. But definitely appreciate your advise, it is much needed.

 

[Bay Retriever]

Thank you all for your recommendations, I am in Toronto and am scheduled to launch on May 5/22, I am thinking I had better postpone until I have this exhaust issue resolved. I just had the rebuilt Caterpillar engine reinstalled yesterday, I have been working with suppliers of flexible exhaust hoses so that the hose has a least a few bends in it. I have also seen stainless steel exhaust flappers that appear to provide a better barrier to sea/lake water from pushing into the engine. But definitely appreciate your advise, it is much needed.

My limited knowledge of the threat posed in this thread makes me more than nervous. I have 2004 Mainship 400, with a single Cat 3126 engine. Does anyone have any diagrams or pics related to identifying and fixing this water egress in the muffler problem?

T MACDONNELL

 

[Keysdisease]

I have also seen stainless steel exhaust flappers that appear to provide a better barrier to sea/lake water from pushing into the engine.

https://www.go2marine.com/exhaust-p...rJSLeJISeOlGV5psuMhQfNXIDFsbiVkhoCsCsQAvD_BwE

 

[Bay Retriever]

https://www.go2marine.com/exhaust-p...rJSLeJISeOlGV5psuMhQfNXIDFsbiVkhoCsCsQAvD_BwE

Where exactly does this flapper get installed?

 

[Keysdisease]

Often there is a stub of pipe where the exhaust exits, it clamps on that stub

Where exactly does this flapper get installed?

 

[Keysdisease]

On the 390 because of the bustle the exhaust exits at the aft starboard corner. You could cut the ring of rubber off the part and screw the
"live hinge" of the part into he hull just above the exhaust outlet

Where exactly does this flapper get installed?

 

[jleonard]

My limited knowledge of the threat posed in this thread makes me more than nervous. I have 2004 Mainship 400, with a single Cat 3126 engine. Does anyone have any diagrams or pics related to identifying and fixing this water egress in the muffler problem?

T MACDONNELL

To my knowledge, the 400 did not have hydrolock issues.
It was only the 390s and limited to a couple of production years when they changed from the 3116 CAT to the 3126 CAT.

But adding a flapper as shown above can't hurt.