Bad dewinterization- any thoughts

[GUY_RPM]

Got the boat put back together tonight then hooked up the fake a lake and started the boat. It started fairly quick but sounded a little rough, it did not want to idle. I rev'd the motor to about 1500 RPM and it sounded ok. When I backed it back to idle it still sounded rough like it wanted to die. I turned it off before it died. Went to start it again an it just clicked once then nothing, no rotation of anything. Thought I would switch to other battery just in case the battery went dead over the winter, on the other battery it did the same thing, just one click and nothing. Both batteries spent the winter on a battery tender and both batteries show that the batteries are charged. Checked oil and it looked great. Oil was changed last fall when the boat was winterized. I know it could be anything but just thought I would get your ideas.

[GUY_RPM]

A little more info - the starter did not click over and over like it is a bad starter. Now it could be a locked up starter. I am looking forward to your input.

[bryce2320]

My starter went out on me this year. But it had warning leading up to it frying. Like a really hard and slow cranking the last 3 times out. Hopefully that is all it is.

[chpthril]

I dont like to trust any kind of gauge on a charger. I like to put a meter on and see the true battery voltage. You could have 2 bad batteries or you could have a hydro-locked engine. check/test the batteries. then try to turn the crank by hand with a ratchet handle and socket on the crank bolt, unless its an PM engine with raw water pump on the crank. Pull the spark plugs next.

[GUY_RPM]

I will say when it cranked over and started the battery seemed strong. I believe the motor is a Mercruiser 350 Magnum.

[GUY_RPM]

What is a hydro locked motor?

[chpthril]

What is a hydro locked motor?

water in one or more cylinders.

[GUY_RPM]

If I had water in cylinders wouldn't the oil look funny? Water in the cylinders would mean a cracked block or heads? I winterized the boat myself very thourghly. I looked at the oil, looked fresh and clear.

[Ruger761]

Far as the batts go sounds like a loose or corroded connection or bad solenoid on the starter. So checking connection and then starter, if batteries are truely good, whould be where Id start. Rough idle is probably bad gas more than anything on that end. What did you do with the gas during winterization? And were you running ethanol gas or straight gas?

Doesnt sound like a hydro-locked motor to me, but that can be ruled out pretty easy by turning crank by hand or poping out spark plugs. (On a fresh oil change and only running that short of time, you might not see milky oil if it were a cracked cylinder wall only, but it would show up very soon or longer run time)

[chpthril]

Water can enter the cylinder through a cracked or rusted out exhaust or rusted out head gasket and hydro-lock the engine without ever getting into the crankcase and mixing with the oil to the point of looking milky. Water entering a cylinder will also cause a rough idle.

[Ruger761]

Im not disagreeing with you, just didnt fully sound like a hydrolock to me. Plus I just try not to jump to the worst case possible when there are other things that could be going wrong that need to be checked out as well. Solenoids, battery connections due corrode and loose good connection to the point they will only kick the solenoid but wont crank the motor over. Gas over the winter goes bad very easy especially with ethonal so pretty safe to say it could be bad gas depending on what he did to winterize it and what kinda gas it had in it.

True exhaust and gaskets can cause it as well. Once the engine sits water in the cylinder will penetrate thru the rings and will get into the crankecase is what I was leading to far as he wouldnt see it for a longer time.

[chpthril]

It doesnt fully sound like a bad starter, but it could be. Doesnt fully sound like a corroded cable or bad connection, but it could be. From a logical diagnostic process, its quicker and simpler to attempt to spin the engine over by hand. Even pulling the spark plugs seems like a more logical step over pulling the starter and taking it to someone to test, only to have it show ok and return to the boat no closer then you were before.

Now, I did not jump to the worst case possible. If you reread, I did suggest starting with the very basics, battery voltage. Battery voltage at the batteries, then move to battery voltage at the starter. One can also do a voltage drop test on the main battery cables. This is the best way to find a bad cable, as sometimes corrosion will be under the insulation and not visible to the naked eye. A cold engine will require more torque to spin over. More torque from the starter = more current draw from the battery. The OP did indicate that it seemed to crank over strong the first time out, but ran rough from the beginning. After shutting down then trying to restart, all the starter would do is click. You can also reread to see that I had previously explained that by turning the engine over by hand and/or pulling the plugs, a hydro-locked cylinder can be either ruled out or verified. And yes, water will eventually seep past the piston rings and end up the crankcase. But since water and oil do not mix, the water will fall to the bottom of the oil pan and not easily detected on an engine thats not running. It takes the running engine to churn it all up into the milkshake we've all come to love. The only way to detect a small amount of water in the oil of a non running engine is to drain the oil into a clear container and let it settle. If there is a large amount water, one might notice the oil lever being higher then before. But only if you knew where it was before.

Spoiled fuel can most certainly explain the rough idle, but will not prevent a starter from turning over the engine. Ethanol blended fuel doesnt really spoil any faster then 100% gasoline. The ethanol just adds a whole new set of conditions to work around. Ethanol greatly increases the moisture absorption rate of the fuel, which can lead to a filled water separator. The next think to be on the look out for is phase-separation. Once enough water is absorbed, it will fall out of suspension and gather in the bottom of the tank, rather then being carried out with the fuel and either caught in the water filter or run through the engine and out the exhaust. Once there is phase-separation, these layers collect around the fuel pickup and lead to a no-start condition. In this case, the engine should spin over, but will not fire and run on its own.

I hope this clears up where im coming from.

[Ruger761]

Mike Im not trying to p*ss you off or disagree with you one bit, we both just have different approches to figuring out a problem . If I did p*ss you off, I'm truely sorry that was not my intent at all. And I do see your very valid points to your meathod of finding out the problem.

[GUY_RPM]

I believe it is bad batteries now. Pulled the boat out into the sun light this morning and checked oil, looked as clean as new which it should since I just changed it. Just for the heck of it turned batteries on and tried to crank it to see if the motor would rotate. It did rotate a couple of times till the battery would not turn it anymore. Maybe my battery tenders are bad, they were cheap ones from Wally World. Going to get batteries checked today or tomorrow.

[chpthril]

Not pissed in any way so nothing to apologize for. Im all for difference of opinion and I am always happy to elaborate deeper to reinforce my point. This is what adds use full content to the forum.