After long layup, no exhaust water! HELP!

[blhickson]

Long story short: c&c33-1 has been on the hard for 3 yrs. Owner stepped in to fire his embezzling yard mgr and has finally completed the faulty thruhulls and launched my boat. After replacing all fuel lines, filters, spark plugs, checking for compression and spark at coil and plugs, fuel tank had been cleaned and reinstalled with fresh fuel, and starting then cleaning carb 4 times, my sweet A4 started like a champ and runs with a lovely hum. Engine is raw water cooled v-drive. Problem: no exhaust water. What I’ve done: good flow from raw water thru hull to pump (had cleaned the raw water strainer). Impeller was changed and spins with its shaft very fast. Turned off raw water thruhull and using 5 gallon bucket to monitor flow. Water is getting past the pump. Water got to the t-stat housing (t-stat removed). Removed exhaust flanges both front and back (my exhaust flange is near the gear drive facing the bow but I removed both to check for blockage, both were bone dry but clear of blockages with coat hanger ream test). I can’t make heads or tails of the back flushing diagrams in the Owners Manual from MMI. I can’t find any “threaded input” near my alternator to remove to install a hose fitting to flush. What am I missing? The blockage must be near the diverter fitting, and the Moyer manual suggests that removing the alternator may be necessary to access this. Is there any other way? I need to get boat out of the yard’s dock ASAP. I’ve missed a week of work getting baby back to a marina and to get this done ASAP.

[blhickson]

Just wanted to add:

My cooling system looks like Rigspelt’s Late Model diagram in that forum. Late model A4.

[Dave Neptune]

Barbara, there is a 1/8NPT fitting on the block just under the alt towards the accy drive. It may have a plug or a pipe and a cap for winterizing.

Dave Neptune

[blhickson]

Thx !

I have a 6 inch outlet from the bottom of the area behind the water pump and auxiliary drive. Is that it?

[Dave Neptune]

That's the way mine was originally set up. Be carefull it is notorious for snapping off and/or being plugged.

Dave Neptune

[JOHN COOKSON]

What Am I Missing Here?

Water got to the t-stat housing (t-stat removed). Removed exhaust flanges both front and back (my exhaust flange is near the gear drive facing the bow but I removed both to check for blockage, both were bone dry but clear of blockages with coat hanger ream test).

Water is making it to the thermostat housing (t-stat removed) but not getting as far as the manifold. The blockage is inside the thermostat housing or in the hose connecting the thermostat housing to the manifold????

TRUE GRIT

Try clamping the bypass. Maybe by forcing all the pump output though the engine it will clear a passage so the water will start flowing through the engine.
Be careful running the engine to long without water coming out the back the boat. Hoses and mufflers after the engine can get fried with hot exhaust when there is no cooling water through them.

[edwardc]

Barbara,

The hose barbs on the manifold are frequently attached using 90 degree elbows. These elbows are notorious for trapping rust flakes, broken impeller bits, etc, and becoming clogged.

Easy to check, easy to replace.

[ndutton]

Removed exhaust flanges both front and back (my exhaust flange is near the gear drive facing the bow but I removed both to check for blockage, both were bone dry but clear of blockages with coat hanger ream test).

Please clarify exactly what is meant by 'exhaust flanges'. If taken literally, the area inside the flanges is dry exhaust and should be dry at all times. The flange is what the large exhaust pipe connects to, held in place by 2 bolts or studs/nuts.

[blhickson]

Neil yes those flanges. Thks for letting me know the exhaust manifold is supposed to be dry. I did not put water in it.
Here are pix of my cooling system. I back flushed through the 6” brass outlet near the alternator and clamped the crossover tubing but there was so much leaking water there may not have been enough pressure to push out the grunge. Where would it have come out?
I also back flushed at the two elbows after the t-stat. Where would any flushed grunge come out?
Still nothing coming out of exhaust behind boat. What’s next? The exhaust and muffler system? How would I go about flushing that?

[ndutton]

I suggest removing the 5/8" black hose and it's 45° elbow in the first picture right above the exhaust blanking plate. That is where the usual blockage is found. If nothing is found there, remove the little square elbow in the fourth picture and check in there.

[JOHN COOKSON]

I'd flush the manifold using city water pressure and be done with it.
I got sick and tired of crud accumulating at various angled barbs in the manifold so I went to straight barbs at the inlet and outlet. Problem solved. Not the luxury of that much room on some boats.

TRUE GRIT

Edit: Recall you are in bit of rush to get 'er going? Maybe not the best time to do all of the above?

[blhickson]

I actually had to go back to work after being out for a week so I’ll get back to her this weekend and report after. Thanks for all info.

[blhickson]

Success, I think.

I put together a flushing kit and got clear water out of the exhaust. Thanks for all the great info. The blockage was in the last manifold exit elbow. Now I’m not sure if the temp sender is working. It was working when I ran the engine without exhaust water last weekend. (I did not let the temp get above 160 before shutting down) I may not have let her run long enough to see a temp rise. How long should that take? I wouldn’t think 10-15 minutes. We’re in Charleston after all.
Neil, I saw your wring diagram in the other post area. Can you see the water temp sender in any of my pictures? I may be looking at the wrong thing.

[zellerj]

If you are in a hurry and just want to know what temperature your engine is running, use an infrared thermometer that you can buy at any auto parts shop. Just point and shoot at various points on your engine and you know the operating temperatures.

Generally the temperature gun will see hotter tenps the closer you shoot to the spark plugs, and cooler elsewhere. If you see head temps away from the spark plugs of 180 F or lower, you are good to go.

Best
Jim

[JOHN COOKSON]

Now I’m not sure if the temp sender is working. It was working when I ran the engine without exhaust water last weekend. (I did not let the temp get above 160 before shutting down) I may not have let her run long enough to see a temp rise. How long should that take?

Your cooling system may now been such good shape that the engine running so cool that you are not getting a reading on the gauge. Betcha this is what is happening.
To confirm use a IR thermometer, as previously mentioned.
In any case this will be good enough to get you out of the yard and back to the slip or where ever you're headed.

TRUE GRIT

PS: This same thing happened to me. The cruise RPM temp rose slowly over a period of couple of months. One day there was no water out the back of the boat. Flushed the manifold and the temp dropped back to ~ 120 degrees.