[C320-list] Aqua lift mufffer

[danny at jensenshouse.com]

Sent from my iPhone

> On Aug 12, 2015, at 8:52 AM, Chris Burti <clburti at gmail.com> wrote:
> 
> Danny,
> Great write-up...I'd like to use it for a Mainsheet article with your
> permission. Any pictures available?
> 
> Thanks,
> Chris Burti
> C-320 IA Technical Editor
> Commitment, #867
> 
> On Wed, Aug 12, 2015 at 9:45 AM, danny jensen <danny at jensenshouse.com>
> wrote:
> 
>> I have commented on this subject before so I hope you all don't mind my
>> re-post on this subject. My impression is that mufflers need to be replaced
>> proactively every 10 years along with mixing elbows. This is cheap
>> insurance because you will float your floorboards and get soot inside your
>> boat. It is ugly. Just pay the $375 for a new muffler and save yourself the
>> aggravation.
>> 
>> Here are the details of my mixing elbow / aqua lift muffler replacement
>> project.
>> 
>> I have about 500 hours on a 2004 C320 with a Yanmar 3GM30F-YEU. The
>> mechanic recommended I change the mixing elbow in the next 12 months.  The
>> U Mixing Elbow inside was corroded at the point where the raw cool raw
>> water mixes with exhaust. The riser appeared to be in good shape but the
>> two parts looked to be bonded together and my mechanic told me to replace
>> the entire assembly Elbow, riser and join. I read several owners accounts
>> of failed mixing elbows and mufflers / muffler repairs. The lead time to
>> get a muffler from Catalina was estimated to be 2 months.  The general
>> consensus was to replace the muffler after about 10 years. Mufflers seem to
>> fail mostly near the screw holes in the corners. Some owners think this is
>> due to vibration from the engine exhaust hose. I used Jeff Hares rule and
>> decided to replace the muffler on my schedule instead of the boats schedule
>> especially because of  the 2 month lead time for the muffler. The cost of
>> the muffler from Catalina was $374.
>> 
>> I contacted Ken Roy at Catalina and gave him my hull number and some
>> pictures and dimensions of my existing muffler (it is for sale now). Ken
>> asked for some more dimensions. Ken sent me back a picture of the muffler
>> he proposed to make for me and requested payment. It took about 2 months
>> total to get the muffler.
>> I ordered the gasket, mixing elbow, SS joint and riser exhaust from
>> Bayshore Marine(see below). Next, I considered the muffler vibration issue.
>> Some owners felt that a hump hose would isolate the vibration from the
>> engine to the muffler.  The existing wet exhaust hose connecting mixing
>> elbow to muffler input was a 22 inch 2 in. id.  I decided replace with 2
>> hose segments of more flexible trident corrugated exhaust hose joined
>> together with an exhaust hump hose I purchased from Catalina Direct.
>> 
>> Here are the details. The procedure took about 3.5 hours including driving
>> home once.
>> 
>> 1.        I turned off the raw water thru hull,  disconnected the 3/8 hose
>> connection at the elbow, the 4 riser exhaust bolts came off with no
>> problem. Then I disconnected the elbow from the 2 in. exhaust hose. I used
>> a radiator hose pick to remove the hoses. They came right off with no
>> problem. Don’t sweat removing the hoses.
>> 
>> 2.        I took the old elbow assembly home where I used it for reference
>> to create the new assembly using a vise. I don’t believe you can create the
>> new assembly without the help of a vise and 2 large adjustable 15 in
>> wrenches. Don’t try to make the new assembly on your boat! You will need to
>> twist the 3/8 in input 180 degrees then you will need to create the exact
>> same angle as the old elbow by threading the joint into the elbow and
>> exhaust riser. I used high temperature anti seize on the joint threads
>> before assembly.
>> 
>> 3.        I used a gasket scraper to easily remove the old gasket. Then I
>> applied some high temp gasket seating material to both sides of the new
>> gasket and bolted the elbow assembly to the motor.
>> 
>> 4.        I removed the 4 stainless screws securing the muffler to the boat
>> and I removed the output exhaust hose from the old muffler using the
>> radiator hose pick. The hoses come off the muffler without any problem.
>> The muffler comes out of the boat without any problem.
>> 
>> 5.        I put the new muffler in place and connected the output exhaust
>> hose without any issues. I found the screw holes on the new muffler did not
>> match the screw holes on the muffler.  I could get the 2 screw holes
>> forward to line up but then the aft screw holes with not align with the
>> existing holes. Access to the forward inboard screw is somewhat limited so
>> you will want to match the forward inboard screw with the existing hole
>> then use a drill motor to self tap new holes with the muffler in place. The
>> existing self tapping screws were in good shape and I did not need to drill
>> pilot holes, I just drove the screws into the glass with the muffler in
>> place after I screwed down the forward screws. Apply a good amount of
>> silicon grease to the muffler drain.
>> 
>> 6.        I used a sawzall to cut an 8 in and 13 in segment of corrugated
>> exhaust hose then I joined them with a hump hose using double hose clamps
>> on each side of the hump hose. Then I connected the hose to the mixing
>> elbow and the input side of the muffler.
>> 
>> 7.        I turned on the thru hull and ran the engine. White fiberglass
>> chips from the new muffler were spitting out the exhaust for a while. No
>> leaks. The hump hose appeared to do the job limiting vibration. I left the
>> rear engine cover off and took the boat out in open water and ran the motor
>> up 3000 RPM. I went below and to my surprise I saw smoke coming from the
>> exhaust riser side of the stainless steel joint nut!  No water. It appeared
>> that the joint was oozing and burning anti-seize.  After about 10 minutes
>> this smoking stopped.  I’m assuming this is normal but it spooked me. I’m
>> going to put a co2 monitor in the aft cabin to make sure I don’t have gas
>> leaks.
>> 
>> Parts:
>> bayshore marine:
>> 128370-13201 gasket     $4.92
>> 124070-13520 U mixing elbow    $169.33
>> 128370-13610 riser exhaust     $130.39
>> 104214-13580 joint                 $28.79
>> Note:
>> 27233-250000 plug            comes with 124070-13610
>> 124070-13300 elbow 3/8    comes with 124070-13610
>> 
>> Parts from Catalina Yachts (K... at catalinayachts.com)
>> 1 Muffler $374 plus Shipping
>> 
>> Parts from Catalina direct:
>> High Temp Anti-Seize Compound (#Z2858): 1
>> Item Total: $15.95
>> Exhaust Hump Hose 1-5/8"I.D X 6" (#Z2152): 1
>> Item Total: $31.49
>> 
>> Tools Harbor Freight
>> 8" Radiator Hose Pick $3.99
>> Carbon/Gasket Scraper $2.99
>> High Temp Gasket seating compound
>> 
>> MMI Marine
>> TRI252-2004
>> TRIDENT CORRUGATED FLEX SAE J2006 MARINE WET EXHAUST HOSE (HARD WALL WITH
>> WIRE)  - 2 Feet  $15.00
>> BUA70HSS36C
>> BUCK HOSE CLAMPS S/S FROM 1 13/16" TO 2 3/4"        4 $8.00
>> 
>> Danny Jensen
>> A BOA VIDA
>> Hull 972
> 
> 
> -- 
> Chris Burti
> Farmville, NC