2008 Mercury 60hp 4 stroke EFI Loss of Power/Cooling/Thermostat Problem

[mustfishjoe]

OK! I think I finally have this posting a new thread down...at least I hope so as this is my 4th try!!!

Anyway last year while out fishing and on the way back in upon going to full throttle to get up on plane my 60 Merc starting "bogging-down" acting more like it was "missing" or a plug was "fouling". Returning the throttle to the idle position stopped the problem. Tried it again...and same thing happened. Finally just returned to the dock on idle/slow speed. As I can remember...the cooling system seemed to be "peeing" fine.

BTW...the 60 is mounted on a 2008 Lowe Stinger Modified 'V' fishing boat. Rig was purchased new and has been serviced only by an authorized Mercury/Lowe Dealer since new. I REALLY "baby" my boats!

Anyway...since it was the end of the season I just took the boat in for the problem and winterizing. After explaining to the Service Manager what the boat/engine was doing he commented...AGAIN...as I can remember...that he thought it might be "coil"...maybe "injector" (which part I DON'T REMEMBER) related and that Mercury had issued a Service Bulletin regarding the issue.

As it turned-out it was neither. The Tech reported that I had encountered a problem with my thermostat getting plugged-up with silt/sand and all that was required was for him to remove the thermostat and clean-out the housing area. I was kinda surprised at this as like I said...engine seemed to be "peeing" fine. BUT I TRUST my dealer and his Techs 1000% so maybe I just misunderstood something....IDK!

Fast-forward to this year. I keep my boat "Up Nort" at our Camp we have on a small chain of four lakes in the U.P. of Michigan. While the lakes are 25-35 feet in depth the channels connecting them ARE shallow and I'm sure this is where I picked-up some silt/sand. Anyway we have been using the boat all year without an issue UNTIL a week or so ago when the same problem from last year started again.

Guess from this point on we'll be using the trolling motor to traverse the channels!!! ;-) ;-) Lesson LEARNED!

I'm trying NOT to go thru the hassle of trailering the boat home to Illinois to be looked at and I'm hoping this is something that my son and I might be able to mess with, with the boat in the water at our dock. While I'm NOT a "Tech" I have worked as a Parts Guy my entire life in the car business so I DO have some knowledge/mechanical ability. Probably enough to get me in trouble ;-) ;-) I've made sure I have an extra thermostat and gaskets.

Sooooo my question is...have any of you ever experienced this and if so what did you do to correct it? Is it as simple as pulling the thermostat/cover and cleaning the housing or do I need to be doing more? Any other "flushing/cleaning" ideas?

Would really appreciate any help/advice you guys might have.

Thanks much!
Mustfishjoe

 

[Timestep]

Re: 2008 Mercury 60hp 4 stroke EFI Loss of Power/Cooling/Thermostat Problem

Two bolts with a 10mm socket and the thermostat is in your hand. Clean it it, be careful with the gasket and put it back ?

Does your warning horn beep when you first switch the ignition on ?

Dave

 

[mustfishjoe]

Re: 2008 Mercury 60hp 4 stroke EFI Loss of Power/Cooling/Thermostat Problem

Two bolts with a 10mm socket and the thermostat is in your hand. Clean it it, be careful with the gasket and put it back ?

Does your warning horn beep when you first switch the ignition on ?

Dave

THANKS so much for the quick responce!

Sorry I just saw it this morning!

The warning "beep"...My son was out fishing with the boat when this happened again. He's not a "kid" anymore (33 years old....YEAH...I'm an old fart ;-)) and very responsible BUT he must have my memory and doesn't remember if the warning beep activated or not.

I should double check my owners manual but I believe the beep would indicate an overheating condition?

Thanks again for the advice REALLY APPRECIATE IT!

Joe aka "mustfishjoe"

 

[Timestep]

Re: 2008 Mercury 60hp 4 stroke EFI Loss of Power/Cooling/Thermostat Problem

Does your warning horn beep when you first switch the ignition on ?

This checks if your beep/buzzer is working every time you go out.

Dave

 

[mustfishjoe]

Re: 2008 Mercury 60hp 4 stroke EFI Loss of Power/Cooling/Thermostat Problem

Does your warning horn beep when you first switch the ignition on ?

This checks if your beep/buzzer is working every time you go out.

Dave

Hey Dave...YES! It DOES beep when we turn ignition on prior to starting. I'm sorry...I had misuderstood your original comment thinking you were referring to some other warning beep. HOWEVER....that being said I don't believe...as I can remember...that we did hear a warning beep during the bogging-down encounter so????

Just received the new thermostat yesterday...MAN it's "tiny"! Guess I'm use to the car thermostats ;-) - I'm a Parts Manager for a Honda Car Dealership - so it's making more sense to me now where I could see this tiny stat getting plugged-up especially with some muddy silt. We're HOPING that's the problem ;-). Guess we'll find out this weekend as we're heading "Up Nort" tomorrow night. I DID set this rig up as my "retirement boat" and purely for fishing. I have a 9.9 Merc "Kicker" as well so if worse comes to worse I'll/we'll just use the "Kicker" for another month or so until I can trailer the rig back to Chicago for the "Professionals" to look at.

Ya know...now that I'm 61 I'm less and less inclined to take-on issues that I'm not totally familiar with but this seems so simple that if I don't I'll be second-guessing myself all winter ;-) ;-)

HEY! I noticed your location as "England"...WOW! although working in the business I do and doing so much online and with computers it STILL amazes me how the Internet has sooooo "shrunk" our world! THANKS AGAIN so much for taking the time out of your day....half a world away...to offer me the advice you have. I REALLY appreciate it!

Have a GREAT DAY Dave!

Mustfishjoe

 

[Timestep]

Re: 2008 Mercury 60hp 4 stroke EFI Loss of Power/Cooling/Thermostat Problem



Hi Joe

Well, that's a mystery. My first 60efi overheated, went into limp/low-power mode, but the thing would beep all the time.

Yes, the thermostat it tiny, you can recover them by soaking them in white vinegar. These engines don't like salt water and a lot of things. I now flush mine with clean fresh water after every use on the tidal river Dart (click on the image above).

Regards

Dave

 

[marinemec]

Re: 2008 Mercury 60hp 4 stroke EFI Loss of Power/Cooling/Thermostat Problem

Hi i have a 2003 mercury efi that had the same problem. my problem was that the tell tail was pumping fine or thats what i thought. anyway cut a long story short after checking thermostat impeller etc my issue was the rubber grommet below the power head on the adaptor plate. the cause was corrosion was squeazing the grommet and restricting water flow. fine at idle but when running up the revs alarm came on and engine went into safe mode but ran fine at idle. just an area to think on if you dont have any joy with the thermostat. engine has only 130 hours although 10 years old it was flushed with fresh water after most runs out.