overheats at highend in warm summer water

[ricknel]

i have a 1987 mercury 60hp 3cyl auto lube that the heat alarm goes off in
warm summer water(over 75degrees).i can run the heck out of it in 60-70
degree water in spring at 5200to 5600 rpm and no alarm??? this has been
on going for 4 yrs.the water pump has been changed out 3 times by 3 different repair shops here in richmond,va and still no good? water comes out of pee-hole fine. last shop ran it in dyno tank and it never got over 143degrees??...the ser# is b259512 on the motor.
2 yrs ago found out it has no thermostat/poppet parts in water jacket???
dont know if that might make it run ok at high speed? i did find 2 broken
off water pump impellers in water jack this last month. which i thought
would cause this trouble, but no such luck.
if anyone out there could let me know if i should buy all the parts for the
thermostat/poppet assembly and install it........PLEASE LET ME KNOW!!!
I AM GETTING VERY UPSET ABOUT THIS TROUBLE and none of the so called
"EXPERTS" can get this fixed???

ricknel
804-276-2806

 

[Laddies]

Re: overheats at highend in warm summer water

It sounds like possably 3 differant things, the easiest would be a temp sensor has anyone tested it-- when you found the impeller blades did you find all the pieces there could be one lodged in a water passage-- you could have a gasket leaking water under the exhaust plate. The other thing most places that dyno engines do it on a hose which is pressurized so it tell you nothing about cooling problems

 

[ricknel]

Re: overheats at highend in warm summer water

Thank You For Responding ...laddies!

I Did Change Out Temp Sensor Last Year,,but I Wonder If It Is The Correct Temp Sensor And If It Is Just Giving Me False Alarm??

I Also Believe The Impeller That Was Missing Blades Had On Two
And I Found Both In Water Jacket.

It Has A Jack Plate And A Motor Lift On Motor To Plane Out And
Adjust Depth Of Motor In Water. I Have It Down As Far As I Can
With Jack Plate And Trim Works Good Too.

The Exhaust Could Be A Problem ...never Checked It . I Will Call
Shop Today And Discuss That. It Takes So Long For Maint. On These
Motors Around Her In Richmond...they Are So Backed Up With Motor
Troubles.

Ricnel

 

[DuckOfDeath]

Re: overheats at highend in warm summer water

I fought the same problem since I got my '88 Classic Fifty last year. Someone here suggested it could be scale buildup in the water passages or on cylinder heads. When I got in there to investigate I also found my telltale hose was somewhat restricted so I can't be certain what fixed the problem. I sprayed CLR lime and calcium remover on everything under the water jacket but a wire brush was really needed to remove the buildup. Anyhow, did that and it solved it. I run it alot on a cooling lake that sees temps in the 90's.

good luck

 

[ricknel]

Re: overheats at highend in warm summer water

It sounds like possably 3 differant things, the easiest would be a temp sensor has anyone tested it-- when you found the impeller blades did you find all the pieces there could be one lodged in a water passage-- you could have a gasket leaking water under the exhaust plate. The other thing most places that dyno engines do it on a hose which is pressurized so it tell you nothing about cooling problems

hey laddies!

this is rick and i did find one more broken off paddle from old water pump
impeller in water jacket. i took off sparkplugs and removed water jacket cover and probed around all holes and found piece in bottom outlet. put it all back together and this summer in hot water 85-90 degree water it runs fine ...NO MORE ALARMS!!

NOW I'M TRYING TO FIND OUT IN FORUM IF ANYONE KNOWS ABOUT 10%
ETHYNOL GAS TROUBLES IN OLD 2 STROKE OUTBOARDS?
I CANNT SEEM TO FIND ANY GAS STATIONS WITH GAS WITHOUT IT?

RICNEL
THANKS FOR YOUR HELP

 

[ricknel]

WELL I JUST GOT MY 87 60 MERC BACK FROM COOPERS MARINE.HE REPLACED BOTH GASKETS ON EXHAUST COVER/BAFFLE PLATE.
I TOOK MY BOAT RIGHT DOWN TO JAMES RIVER AT DUTCH GAP(BELOW ELECTRIC POWER STATION) AND THE WATER TEMP WAS AT
95 DEGREES AT LANDING......YEA 95!!!! SOUNDS UNREAL BUT TRUE. THE POWER PLANT DISCHARGE IS HOT WATER!
WELL GOT IT UP TO 5,000RPM AND RIGHT AWAY GOT SOLID ALARM FOR OVER HEAT.FIRST I WILL REPLACE HEAT SENSOR.
COOPER DID A WATER PUMP TEST AND COMPRESSION TEST AND ALL WAS GOOD.WE ONLY HAVE ABOUT 2-3 MORE WEEKS
OF WARM WATER TO PUT UP WITH.SO I MIGHT NOT DO ANY MORE ABOUT IT.AND I WILL BE LOOKING FOR A USED 75,80,90HP
MOTOR OVER THE OFF SEASON.THE BOAT IS MAX.HP AT 90HP SO I AM 60 THAT IS 30HP TOO LOW FOR ME AND I WANT SOME
MORE HP!!!!!

RICK

 

[ricknel]

after COOPER'S marine worked on my exhaust port baffle/cover they striped the threads on #1 spark plug.so it popped out of the motor on a fishing trip 1 week ago
had to run my trolling motor to get back to landing.also had another boater tow me to landing.COOPER'S refused to fix the trouble he caused on my boat.so
I called my marine-guru(BRENDA from DUKES DOCK) and she referred me to a guy who lives at the end of WATKIN'S LANDING ROAD here in Richmond.
and he installed a HELICORE in spark plug hole and charged me $50 and now atleast it runs good.

still have 80-85 degree water to run in.i will wait till it cools down to the 70's to fish the fall season.
what a big pain in the ASS!!!

ALSO I do have a deal in progress with another boater to get a 80hp Yamaha 2000yr,he wants $3000 for it.all I have to do is check the difference in weight
between my 60hp merc and the 4stroke YAMAHA.if the weight is close it will work good.

rick