Date: Tue Sep 25, 2001 3:40 pm

With a lot of help from Paul and sweat from working on the engine and worry that I purchased a big engine problem I found the cause.

A simple blockage in the final section of the the system was the problem.

The sea water cooling system consists of

Sea water inlet & Valve


Impeller pump

Oil cooler

Heat exchanger

U tube with vent

Exhaust manifold

IO systematically checked each part and found first the impeller needed replacement. The impeller was frozen to the shaft and I needed a new pump. With the help of the repair shop in the park department near Coyote point marina I got the wheel off the old and got a new pump overnight from the Oregon Jabsco distributor. Jabsco was very helpful. Although sold out they told me where the last few pumps were shipped to and gave me phone numbers as well. After replacing the pump the problem persisted. Low water flow out the exhaust.

After checking and flushing all the other parts IU found a lot of debris from a corroded zinc in the heat exchanger. Still low flow. After disconnecting the u-tube and finding great flow up to there, I was holding the u-tube and exclaiming it must be beyond the tube in either the manifold or riser. Then I gazed into the end of the u-tube and saw a slug. Wow! It was a piece of the pencil zinc lodged in the u-tube.

Imagine my relief when the engine ran at 130 degrees without a thermostat and ~180 with it reinstalled.

The zinc comes in two lengths and the long one does not fit in the heat exchanger without modification. For some reason the zinc corrodes at the base and caused it to break off a chunk.

I plan to replace the zinc with a short version rather than modify the heat exchanger to accept the long on.

Any ideas to prevent corrosion at the base? I was thinking of sealing the base with nail polish to prevent sea water from getting in while still allowing electrical contact to the brass.

Date: Sun Oct 7, 2001 10:43 pm

I have a 5424 Universal Diesel,3cyl. It works fine however on the rear injection port I noticed a little feul is accumulating in the well of the injector. As near as I can tell the feul is coming from the base of the injector. I intended to replaced the copper ring at the base and my manual says it can be unscrewed with a 1 1/16 deep socket or a 27mm deep socket. It ain't so. I got a 1 1/16 deep socket but the thickness of the socket, its O.D. does not allow it seat on the injector because the engine block does not allow it to fit in. Anyone had similar experience? Oddly enough the engine runs fine

Date: Mon Oct 1, 2001 2:13 am
Are you sure the leak is at the block of the engine and not at the nut that attaches at the top of the injector? Try tightning that nut. or check it with a paper towel. Sometimes they can leak.

Date: Tue Nov 6, 2001 9:36 am

The diagnosis of the alternate stroke banging noise certainly leads one to the theory that a connecting rod bearing could be the culprit. Each power stroke, being one of the four cycles, places huge and immediate pressure on the crank. The leak 'source' may offer further clues. Wrist pins, valve train failures generally won't create leaks. But I recommend that you do check the rockers and valve stems first. A broken pushrod or a snapped valve that has punctured a piston will certainly cause a large amount of very wet blow-by that can easily collect and leak from the top of the engine.

If you have not had the pleasure of removing the engine yet I offer my condolences on an interesting project. It certainly "looks" way tougher than it really is however. I did it on a mooring in Road Harbor with a two foot chop and twenty knots of wind.

In actuality, after disconnecting the shaft, the hardest job is done. The various spaghetti is no problem but I do recommend removing the manifold as well, it comes out as a unit after the exhaust hose is freed..

Place a substantial 2 X 10X about four and a half feet long, on-the-flat, and under the unit after removing the lag bolts holding the motor mounts to the stringers. Wedge a 2X6 twartships into the bilge just about even with the stringers (or lag into the stringers) to create a pivot point that prevents the unit from falling onto the engine compartment's bulkhead sill or the bilge once the forward mounts clear the stringer. I placed a 2X4 across the fwd. opening of the main cabin bulkhead as a secure point for pulling and ran the boom vang back to a loop of line on the crank pulley for the effort point. Put the mainsheet tackle on the boom just above and a foot or so forward of the engine bulkhead and support it at that point with the topping lift or a spare halyard to prevent bending the boom. Set the tackle more as a support than a lifting device. A cut piece of 1/2" plywood protects the cabin floor and you roll the unit to starboard a bit and "deliver" the unit with almost shameless ease. Later on the mainsheet tackle and boom can be used to remove the engine from the salon and ship it dockside.