We are on patrol and the slow system triggers an over heat situation.

1.Explain the TPSB becci for over heating, the possible causes and a possible solution.

2.Explain how you would check to see if the slow system sounded a valid warning.

3.Explain the parts that could contribute to an over heat

Good Luck!

When the SLOW system is activated for overheating the source could be "no oil", "water temp" or "hot", "check engine", and "low oil. If the engine is overheating the EMM will activate S.L.O.W which will shut the powerhead down. A flashing "water temp" or Hot means the EMM has identified an increasing overheating condition and will not restart the engine until it cools.

Are you sure it will shut down? If it does shut down at what temperature?

Great answer give me more!!

When the S.L.O.W system has been actuated you must allow time for the engine to cool or it will only shut the engine down. After you allow it to cool you must reset the protection system or the motor will top out at a designated RPM to protect the motor. This is because the computer is reading temps that are not normal. If the problem is fixed then the Slow system should not activate because system is at normal operating temps.

The slow system will shut down the motor when an overheating situation is detected because it was designed to protect the motor from possible damage. To determine if the slow was valid tilt the motor to expose the lower unit. Inspect the water intake ports for any debris. If any debris remove it then place motor back in the water. Reset the slow system and increase the throttle monitoring the water temp. At this time you'll want someone watching the engine to see if water is coming out the water pump indicator. It should be a steady stream and consistant

If cleaning the intake ports restores discharge from the indicator you'll need to run the engine for two minutes in neutral allowing the engine to cool off and the light to go off. If this does not go off after two minutes you must shut the engine down. You'll have to idle the engine at a low RPM to get you somewhere to make repairs.

brown has covered a good detail way to check an over heat, u must also raise the engines and check the intake of the cooling system and visually make sure there is no debre blocking the intake. i always visually inspect the oil tank because the stain lines on the actual tank may be much higher than the actual level of the oil. if you are able to take the covers off the engines this is a good way to look for kinks or pinhole leaks and it also can be a good way to decide just exaxtky is overheated.

Parts contributing to an over heat could be the water intake ports on the lower unit or the water pump indicator not pumping out water. This is an important sign of an overheating situation. It's good to watch the engine to assure there is water going throughout the system. IF no water is being pumped then you should shut the motor off even if there is no overheat warning. This could lead to serious damage to the engine. Stop it before it overheats if possible by looking for signs.

Check the thermostats, if they are sticking shut it's an easy fix.

Excellent response!

Still looking for the operating procedures for an over heat. What is the temp the slow system energizes? What is the temp the system shuts down? (Yes that is a hint)

MK3 Michael welcome and thanks for the input.

I didn't read everyone else's response to the scenario, but there are several different things which can engage the slow system due to overheating:

-Poor operation of the water pump
-Worn impeller
-Corrosion or blockage in the cylinder head
-Restricted pressure valve and/or thermostat
-A slightly leaking head gasket can also contribute to high speed overheating

I'm working on finding the temp parameters. I'll get back to you.

MK3 Zim

Keep up the good work ZIM!!!!

I searched and read and could not find the exact parameters for the SLOW system to kick on/kick off, but from what I know, most marine thermostats open at 160 degrees and are completely open at 180. I would imagine that anything more than a 20 degree difference either above or below would cause the SLOW system to engage. I'm probably way off, but that's my best guess.

Darrel, what make of engine are we discussing?

Gypsy, the model we're dealing with is the Evinrude Vindicator 225hp I believe. They are (or were) the standard engines on our PSU TPSBs.

gypsie,

Hi and welcome!

They are 175 Vindicators made by Evinrude.

Two stroke DFI

I guess I should have stated that before hand!

My guys are familiar with the engines. They are specific application for Port Security Boats.

alright, so I was off by 50hp... woops

Zimmerman that 20 degrees would be a valid reason the SLOW would activate because if the thermostat is off then the Slow system would detect a progressive increase in tempurature. If the thermostat were to open more than the designated temp then SLOW would pick up on that.

This message has been edited. Last edited by: Brownur2ndurlast,

Thanks to j_z and 309 for the answer.

When I was at 313 we were running OMC's.