lower cylinder filling with water

[pamountainman]

Hello all, new here.

I have a 72' johnson 6 hp, the lower cylinder fills up with water, should I start with a head gasket?

 

[LarryA]

Start with determining where the water is coming from. Just jumping in and replacing a gasket is a hit or miss proposition and you could do the working and end up right where you are now.

 

[thudpucker]

What do you mean..."Fills up with water"? Is this while you have the 'ears' on and are running water up past the pump and into the engine?
If its running it can't very well fill with water or it'd hydrolock on you.

If you have the hose turned on too much volumn and pressure you may be filling the exhaust chamber with water and thats backing up into the cylinder through the exhaust.
You could possibly get water clear up to the Reed's that way.

C'mon back and fill us in on what trouble shooting you've done so far.

 

[pamountainman]

I tank tested it in early spring for 15 minutes, purred like a kitten as usual. I took it out, made it a 1/2 mile from the dock, and it started missing very bad, I shut it down, and rode out the trolling motor home. I checked for the basics, air,fuel,and spark, all was ok. Tank tested it the next day, and it ran fine. It shut down again 1/2 mile from the dock, this time I pulled the plugs on the lake to change them to see if I had a cracked insulator, and when I pulled the bottom plug, about 2 oz. of water ran out.

 

[grizzly]

whatever it is you're going to be tearing down the top end, so i'd start pulling it apart. either a head gasket, cracked head, or cracked block is your problem. if you can't see anything you'll have to take the pieces to a machine shop and have them checked. if you can, do a leak down test first. you might be able to see it. my guess is a cracked cylinder wall and as it gets hotter it expands the crack and your leak gets worse, i'm not the most familiar with outboards, but as an auto mechanic that's all i can think of.

 

[Top Cat]

Yep, only way water can get in there is either a cracked cylinder or bad gasket. When you tear it down you will usually be able to see and tell if it's a gasket. If gasket looks good then you have a crack somewhere in the cylinder head. Thats usually a strong little motor, has it been over heated, water pump working ok?

 

[thudpucker]

Now wait a minute here guys. If its running good in the tank it aint the head gasket.

Whats the difference between the level of the engine in the water between the Tank and the boat. IE; is the engine much lower in the water on the boat?

If the water level in the exhaust chamber is high, exceedingly high, a hiccup of the lower cylinder will injest water.

2 Oz of water would have bent the rod if it got in there while the piston was going up n' down.

Somethings just not checking out here! How can it run fine in the tank, and have water in the cylider with just a miss while its out on the lake?

 

[grizzly]

lots of possibilities. as a mechanic i never diagnose over the phone, and here i'm trying to do it 1000 miles away. i'm assuming (something else i try to never do) that the tank water level is similar to the level when on the water, so hopefully it is. another thing is time in the tank with no load on the motor is not a duplicate of pushing a boat 1/2 a mile down the lake plus wind and current. engines often won't exhibit problems, even major ones, until they are under a heavy load. a cracked cylinder would cause a miss (obviously), and the majority of the water he's seeing may be accumilating in the chamber in the time it takes from shutting engine down until he gets a plug removed.

 

[pamountainman]

thanks for the replies, The bad part about tank testing is I can't really open it up for a period of time. Its never been overheated since I've had it(1989), the water pump works fine. I rarely use it very long, I use it to get there, and usually use the electric to work my way back, I may use 1 1/2-2 gallons of fuel per season. Other than that, it has never taken more than 3 pulls to get it going. I can't tell you anything more, but this weekend(mon./tues.), I'm going to pull the head off, and take a look.