Exhaust Manifolds leaking.

[Nids]

I have a 2010 CB 200 with PCM ZR 409; noticed that a few drops of water were seeping through the gaskets under the exhaust manifold pretty soon after started using boat. So, I changed the gaskets with spare set of OE PCM ones. The leak has persisted and I'm not sure why. I unfortunately don't have any of the coastal edition options and I do drive the boat through some salty water in order to get to the ski grounds...are the manifolds/gaskets different for salt water applications? Am considering to change the current manifolds to high performance aluminum ones even though they should technically still have two years left in them (current ones).

[gride]

you need to change the gaskets and probably bolts immediately. Have you been flushing it after every use? Either way check out nautiqueparts.com they should have kits available with everything you need. you could get some s.s. bolts, but i would not worry about that.

[Nids]

Thanks Gride, but why did the leak continue even after putting in a new set of gaskets? There's a systemic issue here..

I flush the engine after every use. Good idea on the s.s. bolts; do you think the iron ones are expanding due to the heat?

[LakeRats]

One reason gaskets leak is over tightening. Make sure you have the correct torque specs and a good torque wrench. Also check the condition of each mating face. They have to be free of rust and should be flat. Put a precision straight edge against each face.

[Nids]

Thanks LR, that's helpful to know; any idea of the torque setting? When I changed the gaskets last time I cleaned off all residue of old gasket and/or rust but I din't use a straight edge..

[LakeRats]

From a marine engine maintenance web site. I always start low and tighten after warm.

http://www.perfprotech.com/blog/arti...e-exhaust-tips

MARINE EXHAUST BOLTS & TORQUE:
Do not use stainless steel or grade 2 bolts to install the risers or elbows. These bolts are too soft and will not hold a torque setting, which can cause leaks at the gasket surface. Bolt torque should be reset after initial startup, while the engine is still warm. Refer to your original manufacturer's engine service manual for specific torque settings. As a rule of thumb we suggest between 30 - 40 Lb-Ft for 3/8 fasteners threading into cast iron and 20 – 25 Lb-Ft for 3/8 fasteners threading into Aluminum. HOWEVER THE MOST IMPORTANT THING TO REMEMBER WHEN TORQUING MARINE EXHAUST PRODUCTS IS TO PERFORM IN A UNIFORM PATTERN IN ABOUT 2-3 SEPARATE SEQUENCES. 1) 10 LB-FT FOLLOWED BY GOING ON UP TO 15 – 25 LB-FT THEN FOLLOWED BY TAKING THE TORQUE UP TO THE FINAL RATING. THE TORQUE SHOULD THEN BE CHECKED AFTER RUNNING THE ENGINE FOR 30 MINUTES THEN AGAIN AFTER 20 HOURS. Never use anti-seize type products on bolts or studs as this can allow for loosening of the parts.

[jmo]

This isn't covered under warranty? The boat is only a couple years old, and while I am not an expert, I wouldn't think replacing gaskets should be something you have to do on a three year old boat? Possible they weren't torqued correctly at the factory?

How many hours do you have on it?

[Nids]

This isn't covered under warranty? The boat is only a couple years old, and while I am not an expert, I wouldn't think replacing gaskets should be something you have to do on a three year old boat? Possible they weren't torqued correctly at the factory?

How many hours do you have on it?

JMO, it's probably under warranty but I live in Africa (had the boat shipped here) and there are no Nautique or PCM dealers or reps in my region. I think it was torqued wrong from the factory; I've owned boats before and never had this problem; I've got about 100 hours on the engine... Strange thing is that my brother has a SN 215 and he had the same issue. We ordered our boats about a year apart soooo....could it be a factory fault? We do drive through patches of salt water before getting to the ski grounds which are located in mostly fresh water. But still, we both flush the engines with fresh water after each outing and although we don't have 'coastal' engine options the manifolds should not have been prone to leak so soon after purchasing (under any normal conditions).

[laurie8888]

i have sn200 with 160 hrs and have same problem with rust marks showing on the inside of the manifold...probably dripped down from gasket.
my previuos sn 206 did the same and i eventually got water in oil, i am in salt and also flush

sound like a design issue

[Nids]

eventually got water in oil, i am in salt and also flush

sound like a design issue

Sounds pretty bad; yes, it's sounding more like a design issue now. Thanks for the input, very helpful.

[jasper]

There is good advice in some of the posts above. I would emphasize the advice of ensuring the surfaces adjacent to the gasket is smooth and clean, including no paint. I snapped several bolts in the removal process when replacing gaskets once (ouch) and had to purchase another riser. It came with the surface facing the gasket painted black, just like the rest of the riser. The paint must be removed and the surface needs to be straight and smooth. No leaks with the two replacements I have done so far.

[BenjaminHambling]

I'm running a pair of 196s and a 211 on the sea for commercial use. Salt water is murderous towards our tow boats, with us running them 6 days a week 7 hours a day, however we do flush them every day with fresh water. This surves its purpose of reducing a build up of crap in the exhausts that would otherwise reduce the flow of water to cool the exhausts. We had a boat last year that was completely clogged and overheated to the extent that the fiber glass exhaust completely melted. It turned out the previous owner had NEVER flushed the engine (even though he ran it on the sea) Two new exhaust manifolds and 2 new risers later the boat was back in the fray.

What we DO do is change the gaskets every year when winterizing. Its a quick enough job and it means that we don't have to worry the following summer. I'd rather have to take time to tinker than have salt water seeping into the valves and destroying the engine. Because if its running down the outside, you can bet its running down the inside, not matter how much you flush it. Take everyone's advice, make sure the surface is flat and clean, tighten to the specifications, and keep an eye on it. Luckily for us the company pays for replacement parts, hate to think of someone having to folk out on their own.