muffler petcock

[clifford Rieders]

So I am motoring along and I HEAR A hissing sound. I look at the muffler and steam is coming out of the center of the petcock on the 4-5 year old aqualift replacement muffler that I purchased directly from catalina. Turning it tighter or removing it made no d 8)ifference. Steam and fumes came out; no water. Anyway I stuck something temporarily down the center of the petcock opening and everything is fine. What was that all about?  Cliff

[Ron Hill]

Cliff : I ASSUME that you have a MKI C34??? 
You didn't mention what the engine temperature was doing or if you were getting water out of the exhaust.  If the temp was going up?, I'll guess that you weren't getting enough or any cooling raw water??  Could have been a blade/s off the impeller, something stuck in the raw water intake or a water hose blockage. 
I've never heard of steam coming out of the muffler drain!! 
You should be able to get a new petcock from Catalina parts as they make their own mufflers.   

[isabel98]

A hissing sound and release of steam is not good. you have an overheating sitch.. danger , Will Robinson! Besides the defective petcock, You need to make sure you're pumping water and your thermostat is opening up. after you verify these two things if you still are blowing steam or running hot, you need to inspect and clean or replace your heat exchanger..

[clifford Rieders]

Water was coming out of the exhaust and according to the temp gauge everything was running cool. Thats is the big mystery. I let the engine run for a while and motored around a bit. It was probably steam and engine exhaust combination. Isn't the raw water at that stage still steam, until gets pumped out of the exhaust hose; which it definately was?  you've got me worried now. Cliff

[Ron Hill]

Cliff : If you want the readers to help you, it might be nice to inform us what hull # you have and which engine is installed --
ALL C34's are NOT alike !!!!!!!!!!!!!! 

[Stu Jackson]

Dere ain't no steam on OUR tugboats, mon.

A "hissy fit" of water may well sound or seem like steam.  It could well be that your muffler drain valve hasn't been operated or lubricated by you in a  LONG time.

Psst, psst, psst out of the small orifice of the muffler valve could well have seemed to be steam , but could merely be water spurting out, 'specially if the engine temperature is OK.

Let us know.

The reason Ron asks is this: http://c34.org/bbs/index.php?topic=1506.0

[clifford Rieders]

Its Hull #1022, a 1990 boat, the universal 25xp. I take the petcock out each fall when I winderize the boat.

[Stu Jackson]

Thanks, Clifford, you can add that info to your signature so you don't have to retype it.

Sure sounds like you just need a new valve.

[Ron Hill]

Cliff : I've never heard of taking out the muffler drain plug for the winter!!  Think that's part of your problem. With the anti freeze (1 or 2 gal) that you winterized the engine with, the muffler should be OK with almost pure anti freeze in it.
If you really have STEAM, then the engine is overheating!!  The cause usually is lack of cooling raw water (impeller? clogged intake? crimped hose etc), but as mentioned the thermostat could be staying closed.  However, a stuck thermostat will cause engine overheating and should show on the gage and cause STEAM to also come out of the exhaust.  You need to do a bunch of checking.
There little pressure inside the muffler - just enough to push out the water/exhaust.   

[clifford Rieders]

I put something into the center of the petcock to plug it up...where I guess the stem use to be. Engine runs fine and I used it for quit a run. Temp was 170 or so. what came out of the stem seemed to be steam but perhaps was exhaust and some steam. Plenty of water comes out the stern pipe too !!!  Cliff c34, 1022

[Tom Soko]

Cliff,
If your engine was running at the proper temp (not overheating), I'm guessing that what looked like steam was actually aerated water under pressure.  With the pressure of the engine exhaust gas, combined with the water from the cooling system, being pushed out of a very small hole in the petcock, the water was aerated, sort of like what happens with a high pressure sprayer when your bottom is pressure washed.  It sure looks like steam, but is not. 

[Ron Hill]

Cliff : As Tom so ably put it "I don't think you have a problem". 
Get a new muffler plug/drain or clean up the old one you've got.  Install it and leave it in for the winter!! 

[rmbrown]

Whether you leave it in or not, isn't opening it to drain the muffler a good idea when winterizing?

[Ron Hill]

Mike : NO is the answer. 
Part of the winterizing is to suck into and mix in the raw water system - w/anti freeze.  That antifreeze then goes in to the raw water pump, then into the heat exchanger, then mixed with the engine exhaust gases into the muffler!!  ALL OF THOSE ITEMS ARE NOW WINTERIZED!!

If you use a second gallon of anti freeze - you'll probably have pure antifreeze inside the HX & Muffler!! no need to leave any petcock open!!

A few thoughts

[Jim Hardesty]

Do yourself or the next owner a favor and mark the open/close direction of the petcock.  It's called dummy proofing.
A lot easier to do then replace the petcock.
Jim