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Tan
Tan, MerCruiser Certified Technician
Category: Boat
Satisfied Customers: 10665
Experience:  40 yrs. experience with complete engine repairs both inboard/outboard and MerCruiser Certified Technician.
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Pearl, After winter storage, tried to start 350CI 260 HP Mercruiser

Customer Question

Pearl, After winter storage, tried to start 350CI 260 HP Mercruiser application engine. Discovered water in the cylinders to varying degrees. Last Fall, we had drained the riser manifolds and both drain plugs of water. Thought the engine to be fully drained. We left water hoses from manifolds disconnected, and drain plugs open all winter. Current action taken: We removed plugs, cranked engine to remove any water. We replaced plugs, but starter does not crank enough to start engine. It turns very slowly to a stop. We pulled two plugs noting smell of gas, and no water. No appearance of water in oil pan. We note the battery cables on the port side feel hot, but the starboard batteries feel cold. Overall, we feel that condensation may have gotten into all cylinders. Any helpful advice?
JA: Sometimes things that you think will be really complicated end up being easy to fix. The Marine Mechanic I'm going to connect you with knows all the tricks and shortcuts. Is there anything else the Marine Mechanic should be aware of?
Customer: We have charged both batteries to 100%.
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Submitted: 11 months ago.
Category: Boat
Expert:  Tan replied 11 months ago.
Hello. My name is***** get the engine serial number please? I would remove the spark plugs and squirt some oil into the cylinders. Crank engine over. Does it turn better now If yes reinstall the spark plugs crank engine over does it crank better?If no we need to test the voltage at the starter when cranking with a volt meter. Can you do these actions and post back with findings? Remove the flame arrestor from the carburetor and have a friend push the throttle to wide open real quick do you see fuel squirting in the carb? You will have to open the choke plate to see fuel.
Customer: replied 11 months ago.
Tan, We will do so. How do
we get back in touch with you to continue our conversation?
Expert:  Tan replied 11 months ago.
Just post back as you have been. I will be here all day and tomorrow and next week.
Customer: replied 11 months ago.
Let us follow through with your suggestions first. Thanks
Expert:  Tan replied 11 months ago.
Ok.
Customer: replied 11 months ago.
We have carburetor - choke lubricant to spray into the cylinders, rather than oil. We are out in the country, so would take some time to get regular oil. Will this work okay? I will try to find the engine serial #.
Expert:  Tan replied 11 months ago.
Long as it is oil we just want to lube the cylinders with a little oil.
Customer: replied 11 months ago.
Right . . .. Thanks
Expert:  Tan replied 11 months ago.
Your welcome. Let me know what you find.
Customer: replied 11 months ago.
Engine Serial # *****(###) ###-####
Expert:  Tan replied 11 months ago.
That isn't a good number. The serial number should be down by the starter on a metal plate. http://forums.iboats.com/filedata/fetch?id=7081033&d=1400617699
Customer: replied 11 months ago.
We are looking for proper serial #. We put lube into cylinders (no plugs). Engine seemed to turn over faster. Put plugs back in and very slow starter revolution. Solenoid seems to engage quickly, then slow starter rotation. Noted that port side battery connections were warm, while starboard side was still cool to the touch.
Customer: replied 11 months ago.
Battery switch in the "All" position.
Expert:  Tan replied 11 months ago.
Check the cable connections as they can cause slow starter. We will need a volt meter to do some testing if that doesn't help.
Expert:  Tan replied 11 months ago.
Is the carb squirting fuel into the intake when you advance the throttle quickly?
Customer: replied 11 months ago.
We checked connections, and used wire brush on ground wires. We have a new volt meter, so will do this test. Any recommendations as to specific points to connect voltmeter?
Customer: replied 11 months ago.
Serial # ***** is(###) ###-#### Will this work?
Expert:  Tan replied 11 months ago.
Yes test battery voltage on the battery cable connection on the starter with engine cranking. We must have 9.5+ volts. If voltage is lower than 9.5 we have a cable issue. If voltage is good then we have a starter issue. If low voltage put the ground meter lead on the battery negative term. Crank engine. If the voltage increases then you have a bad negative cable or connection.Post back with findings.
Customer: replied 11 months ago.
Tested voltage at 12volts at the starter prior to cranking. We put the voltmeter on the starter (red lead to positive; black lead to ground) and cranked engine. Voltage reduced to 4.5. Starter did not fully engage, and chattering was heard. We repeated test with same result. Starter likely did not fully engage. Starter did fully engage before this test, just cranked very slowly.
On the second part of you test instructions, we need clarification. "If low voltage, put the ground meter lead on the battery negative term. Crank engine. If the voltage increases, then you have a bad negative cable or connection."
We have two batteries. Do we connect the red meter lead to the positive side of the starter, with the negative meter lead going to the negative post on one of the two batteries? A bit confused. Thanks
Expert:  Tan replied 11 months ago.
This is a voltage delivery issue. It doesn't matter on where just on one of the batteries. The ground is common to both batteries or at least it supposed to be.Postive lead on the starter and black lead on either battery try both just to be sure.
Customer: replied 11 months ago.
We actually tested the voltage both ways as you suggested. We had voltage drop to 4 - 4.5 in both cases.
Expert:  Tan replied 11 months ago.
Ok that leaves the positive cable as the problem. Can you pull the battery switch away and test the voltage at the common terminal of the battery switch when cranking?
Customer: replied 11 months ago.
So, we put the red meter lead on the common terminal of the battery switch, and the black meter lead to ground on the battery switch. . . then crank right?
Expert:  Tan replied 11 months ago.
Correct.
Customer: replied 11 months ago.
Checked the common terminal on the battery switch. Prior to cranking, we had 12 volts. During the cranking, voltage dropped to 7 Volts.
Expert:  Tan replied 11 months ago.
Ok now put the red test lead on each of the battery connections of the battery switch and crank engine. Leave black lead on batt neg.
Customer: replied 11 months ago.
We tested each leg on the battery switch. While cranking, the first one reduced to 8 volts, while the second reduced to 9 volts.
Expert:  Tan replied 11 months ago.
Ok now test directly at the batteries when cranking.
Customer: replied 11 months ago.
Ran the battery test. The batteries are measuring at 8 volts for the first battery, and 9 volts for the second battery when we are cranking.
Expert:  Tan replied 11 months ago.
That isn't enough voltage. How old are the batteries? They must be 9.5+ volts to turn engine over correctly. Now as you can see you loose allot of voltage through the cables. From all the tests we have performed the batteries are the problem.
Customer: replied 11 months ago.
Prior to cranking, we had 12 V on each battery.
Customer: replied 11 months ago.
No concerns about the starter? Any recommendations on batteries?
Expert:  Tan replied 11 months ago.
Yes but that doesn't count with no load. When you take a battery in to be checked they put a load test on the battery to determine the health of the battery. Your starter is doing the same thing as a load tester. Now load is just voltage it only counts when you are loading the battery.Starters need 9.5+ volt to crank an engine correctly. You might try charging the batteries and see if they hold up. The average life of a marine battery is 2 years. You want a good marine cranking battery.Get a good name brand battery not Wal Mart of ware house discount batteries.
Customer: replied 11 months ago.
Tan, thank you. One battery is around 6 years old, and the other is older. So, I guess we need to get a couple more of them. Thank you for your time and patience during this dialogue. If the batteries do not solve the problem, we will be back in touch. Thanks again!
Expert:  Tan replied 11 months ago.
Your welcome. Back at you on the patience. If the batteries don't solve the issue then the starter is next. But just by the testing we did I believe the batteries are the problem. Please don't forget to positively rate my help as that is the only way I get paid. Follow up questions are always welcome at no extra charge on this subject even after rating. Thank you....Tan

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