How hot is TOO hot? Water question...

[Glock Diver]

How hot is the water discharge from my motor supposed to be?  I'm running a '98 Johnson Ocean Runner 200hp 2-stroke.  Should the water be Cool?  Warm to the touch?  Too hot to touch?  

Mine's always been very warm, but I never had any issues.  Last time I went out, I set out with (I believe) a weak battery.  I had been working on stuff on the boat all week, and didn't charge the battery afterwards. So shame on me.    But my friend was trying to start it at the boat ramp, and it was taking WAY too much cranking.  He tried for 2-3 minutes, I then tried, and we couldn't start the motor.   Pulled the boat off the ramp, opened up the motor's cover, and popped off the 6 spark plugs.  Very strong odor of gasoline, so I let it evaporate for a while.  One or both of us had flooded it.

After a few minutes, I tried to start it again from the batteries, and no luck. I then jumped it from the truck, and it fired up!  :)  However, after 30 seconds or so, the water temperature alarm sounded.  I felt the water from the motor, and it wasn't scalding hot.  Very warm, but not HOT.  I'm wondering if all that cranking affected the temp?  Or the water pump?  And yes, the motor was either in the water or had a hose connected via earmuffs when I was starting it.
Thanks guys.  

[Capt. Bob]

GD,
Let's take it one step at a time.
I'm not the electrical genius here but these older JohnyRudes need to reach a minimum (rpm) cranking speed in order to fire. The magnets in the flywheel produce the magnetic force necessary to produce voltage via the sensor and charge coils that deliver energy to the power pack to fire off the plugs. It needs to spin up about 300 rpm IIRC to work. 250, 275 ain't gonna get it. A weakened battery would cause that. Spinning but not firing still supplies fuel, hence the wet plugs. Of course, you and your buddy may be clueless on using the electric choke but I bet you guys have started it many times before and know the procedure. The real clue is that it fired with the truck battery (not that the gas evaporated).

That's an easy fix. Charge/replace the battery.

Water temp.
Well when the engine has reached its operational temperature (about 160 degrees) the water would be "warm". The alarm goes off when one of the temp switches (one in each head) closes and triggers the horn. This occurs around 200 degrees. Water is now quite hot. You will feel the difference.

One, do you have a temp gauge in your panel? If so, was it reading high when the alarm sounded?
Have you run the motor since then and does it still happen?

Cranking does result in motor movement and that produces friction (heat) but the real heat comes from combustion so I don't think the excess cranking caused the alarm to sound. More likely a thermostat didn't open and triggered one of the temp head switches.
We need a little more info.

[Glock Diver]

GD,
Let's take it one step at a time.
I'm not the electrical genius here but these older JohnyRudes need to reach a minimum (rpm) cranking speed in order to fire. The magnets in the flywheel produce the magnetic force necessary to produce voltage via the sensor and charge coils that deliver energy to the power pack to fire off the plugs. It needs to spin up about 300 rpm IIRC to work. 250, 275 ain't gonna get it. A weakened battery would cause that. Spinning but not firing still supplies fuel, hence the wet plugs. Of course, you and your buddy may be clueless on using the electric choke but I bet you guys have started it many times before and know the procedure. The real clue is that it fired with the truck battery (not that the gas evaporated).

That's an easy fix. Charge/replace the battery.

That's kinda what I figured.  I noticed that with motor cover removed, the flywheel wasn't spinning as fast as normal when I was cranking it.  That's when I figured we should jump it, and the wheel spun much faster!   And it fired up. Yes, we were using the choke (key push type).  So that part makes sense.  And I did replace a battery, as well as added a 5/5 Amp dual charger.  

Water temp.
Well when the engine has reached its operational temperature (about 160 degrees) the water would be "warm". The alarm goes off when one of the temp switches (one in each head) closes and triggers the horn. This occurs around 200 degrees. Water is now quite hot. You will feel the difference.

One, do you have a temp gauge in your panel? If so, was it reading high when the alarm sounded?
Have you run the motor since then and does it still happen?

Cranking does result in motor movement and that produces friction (heat) but the real heat comes from combustion so I don't think the excess cranking caused the alarm to sound. More likely a thermostat didn't open and triggered one of the temp head switches.
We need a little more info.

No temp gauge, just an alarm/red light.  I was able to hold my hand under the water while the alarm was going off.  It was hot, but not scalding.  Haven't run it since then, but will give it a try tomorrow and let you know if the problem was repeated.

[Capt. Bob]

GD,
When you start the motor (on the muffs). look at the vents on top of the cavitation plate (where the lower and middle units bolt together). They're located just in front of the zinc anode. When you turn on the water to the muffs (installed) water will (should) not exit these vents. Start the engine and watch the vents. Water should not exit them at first. After a minute or so, as the motor warms, water will begin to flow from these vents. This indicates that the thermostat(s) has/have opened. If water does not exit at this point or is not in a decent amount, one or both stats are not opening correctly. Your alarm should sound.

To determine which stat is stuck, you only need to touch the top of each bank (head). On will be much hotter than the other.
Thermostats are not rocket science, high tech designed parts but they play a vital role in the running and protection of your motor. "Loopers", like your Johnson are sensitive to temperature. Too cold and they run bad. Too hot and they lower your bank account.

Let us know if water is coming out of those vents.

[Glock Diver]

Not sure how "tomorrow" turned into 2 weeks later...
OH wait, I know!  Bad weather and Small Craft Advisories for the last 10 days!   :(

But alas, this past weekend was beautiful, and I was able to get out Saturday AND Sunday.  :sunny:  Saturday we went diving off my boat in Venice, and Sunday the wife & I went out around Sanibel.

Back to the water temperature issue- As you mentioned, I did eventually see the water discharge from the small vents, but not at first.  Also, I had zero alarms this time when we went out on the water. Everything was fine. I'm wondering if I have a crappy set of earmuffs?  Maybe they're not supplying enough water to cool the engine?  The only time I've seen/heard that temperature alarm was when I was flushing the motor with the muffs.  


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On the topic of flushing-- does anyone flush the motor via the threaded hose-size port at the back of the motor?  I'm wondering if I flush from this point, instead of using the earmuffs, could I have the same effect without running the engine?  (Trying to think of a way to be considerate of the neighbors when I get home late after a day on the water.  Firing up that 200hp outboard tends to rattle some windows!)

[RickK]

How was the viz on saturday?  I was fishing around venice and the water was real dirty (from the weather the last week) everywhere I was at.  Poked my 170's nose out into the gulf briefly to see if we could get bait but it was pretty rough so I spun around and fished inside. Bunch of boats were heading toward the jetty and it was only 8AM.

You can use the flush port that the Johnsons have but the guy that rebuilt mine told me it didn't do a good job of flushing the impeller that way.  May be ok for your "every other week" startups but use the muffs after a soaking in salt water he said.

[Glock Diver]

Rick-

The viz was horrible on Saturday. Guessing 12" to 18".  After diving in, the 3 of us surfaced and discussed aborting the dive, but we decided to continue since we had made the trip out there.

The waves weren't too bad (we got out at about 10am), but there were some decent swells, that's for sure.

It was my first time out to the "boneyard" and I did find a few fossils and bones (still need to identify them).  One of the other divers found a couple of shark teeth, but no megaladons, which was what I was looking for!

[Capt. Bob]

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On the topic of flushing-- does anyone flush the motor via the threaded hose-size port at the back of the motor?  I'm wondering if I flush from this point, instead of using the earmuffs, could I have the same effect without running the engine?  (Trying to think of a way to be considerate of the neighbors when I get home late after a day on the water.  Firing up that 200hp outboard tends to rattle some windows!)

My take is this.
The hose attachment port will flush a decent piece of the motor and IMHO was designed to flush motors that remain in the water after use.
What it cant do is generate the heat needed to open the thermostats and thus flush the upper end of the motor and at the same time, clear salt from the stats themselves. A major cause of their failure.

But there's always the exception.
My dockmate in the Keys never used the muffs and for ten years flushed with the hose attachment. He suffered no ill effects.
I have used mine once or twice but I prefer the muffs. I like to see the stats open.

[slvrlng]

I was fortunate to have a friend that was in the construction business back in the 70's in SW Fla. Knowing I was a geology major he invited me over to a canal he was digging the other side of El Jobean. I built a screen and we got lucky.
This is the rear molar from a mastadon. I repaired it in a class I took in school so we could make casts from it. The next one is a horse tooth.The big tooth weighs about 5lbs.

[RickK]

cool artifacts

Capt Bob, I never knew to look for the thermostats opening by looking at the vents until you mentioned it - now I look every time.  8)  I do remember that sometimes I would see water there and sometimes not but really not understanding why. If you use salt-away you have a tendency to not run the engine very long so looking for water coming out of the vents means you flushed all the way through.
Learn something new every day.