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1986 MERC 170 4CYL OVERHEATING ISSUE

C

chuckwagon

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"MY 86 SEARAY SUNDANCER HAS TW

"MY 86 SEARAY SUNDANCER HAS TWIN MERC 170 4CYLS, WITH CLOSED COOLING SYSTEMS AND ALPHA I DRIVES. FOR THE LAST THREE YEARS I HAVE BEEN FIGHTING AN OVERHEATING ISSUE WITH THE PORT ENGINE. THE ENGINES HAD LOTS OF HOURS SO LAST YEAR I REPLACED THEM. WHEN I DID THAT I ALSO SENT THE HEAT EXCHANGERS OUT TO A RADIATOR SHOP TO BE CHECKED AND CLEANED. REPLACED THERMOSTATS AND CHECKED FOR ANY FOREIGN MATERIAL IN THE COOLING SYSTEM. TO MY DISMAY I STILL HAD THE OVERHEAT UNDER POWER ON THE PORT SIDE. THE MORE YOU PUT POWER TO IT AND THE FASTER YOU GO THE TEMP GAUGE WILL CLIMB, SLOW DOWN AND IT WILL COOL OFF BUT ALLWAYS IS HOTTER THAN THE STARBOARD ENGINE. SO I CHECKED WITH AN INFARED THERMOMETER WHICH VERIFIED THE ISSUE PLUS WHEN IT GETS HOT THE OIL PRESSURE LOWERS FROM THE THINNER OIL. THIS SPRING I REPLACED BOTH OF THE WATER PUMP IMPELLERS AGAIN WHICH WERE ONLY A FEW YEARS OLD. LOW AND BEHOLD THE PORT ONE WAS ALL DEFORMED BUT NOT BUSTED UP. SO GLEEFULLY I PUT THE BOAT IN FOR SERVICE ONLY TO FIND THAT NOTHING HAS CHANGED. PLUS OTHER OUT DRIVE ISSUES SO I PULLED HER BACK OUT AND RECHECKED THE IMPELLER WHICH LOOKS FINE. I TOOK A BOROSCOPE AND INSPECTED THE PASSAGES UP TO THE TRANSOM WHICH WERE CLEAR. I DEFINATELY HAVE WATER FLOW. ALSO THIS ENGINE IS HOOKED INTO MY HOT WATER HEATER. IM SICK AND TIRED AND CONFUSED PLUS NOW IT SEEMS THAT I COULD USE LOWER GEAR CASE WORK. WHEN I MANUALLY TURN THE DRIVE, SHAFT AFTER I INSPECTED THE IMPELLER, TO MAKE SURE FORWARD AND REVERSE WORK IT FEELS CLUNKY AND I SEEM TO GET EXCESSIVE SIDE TO SIDE MOVEMENT. THIS IS WITH THE UPPER WATER PUMP HOUSING REMOVED. HELP!!!!!!! 4TH OF JULY VACATION IS COMING UP."
 
"If there is no preload pin on

"If there is no preload pin on the driveshaft, this slop is normal because the drivshaft pushes up when running, setting the bearing clearance.
Adriveshaft with the pin pushes it down to set the clearance.
All due to the way the gears are cut
Overheat:
clogged riser
leaking water pocket cover
pump base sucking air
base gasket reversed
warped base
copper connecting tube a bit too short
kinked (maybe internally) water hose gimbal to transom"
 
"Thanks for the good info. I

"Thanks for the good info. I presume that the preload pin you mentioned is a tool used to set up the bearing clearance if the lower gear case is apart. So that's good for me. I thought I might have to disassemble and was not happy about that. I did inspect the riser when I installed the engine last year and it seemed clear. Also replaced the water pocket gasket. So when I get home tonight I'll pull the base and check it out and probably just go ahead and replace the whole thing.
As for as the water hose to gimbal housing, this may be a concern. I Replaced both sides 4 years ago when I replaced the belows. LIke the ones I took Off both sides have a distinct kink in them. The Starboard side runs cool though. I was able to slide the boroscope up through the hose to the elbow going into the transom. Is there any thing that can be done to keep the hoses from kinking? Can I loosen the gimbal housing and replace the hose without messing with the bellows?

Thank You

Brian"
 
Someone said to install it w/a

Someone said to install it w/a slight kink and it will be straight when drive is lowered; which way I don't remember.
 
The water hose fits perfect! I

The water hose fits perfect! If installed correctly and is a mercury part.

If you purchase a after market part the material may be softer and longer then a stock merc.

I have personally replaced hundreds of these and never had a kink.............Well I did when I was learning back a long time ago but only a couple............lol

They fit a certain way that is learned with experience and lots of effort. It aint the easiest job but if done right NO KINKS............
 
"Just so you know, this may be

"Just so you know, this may be the toughest replacement part out back, IE: bellows, shift cable, exhaust bellows.

The water hose requires a significant effort to get it to fit propperly and have a "slight" twist so as to fit nicely on the gimbal housing brass barb fitting.

Make sure you beat the end of the hose (not to much) that goes on the Transom side Plastic tube end with a dead blow hammer to soften up the end of the hose and also a small amount of vasoline can help........

I then stick in a large long screw driver to use as a handle if you will to push and twist it onto the tube all the way you can at least as far as the original one was, A bit more is ok"
 
Yes you can BUT it takes patie

Yes you can BUT it takes patients and practice!!

I would advise to remove the entire gimbal housing and bellows. The bellows from the transom side only and just pull it back far enough to make life easy. This requires pulling the pivot/hinge pins under the trim swithc and trim sender.

God luck...............
 
"Kghost:

"you beat the

"Kghost:

"you beat the end of the hose (not to much) that goes on the Transom side Plastic tube end with a dead blow hammer to soften up the end of the hose and also a small amount of vasoline can help........"

Now that's a lot of work when soaking the hose end in very hot water just a minute before installation will soften it. Vaseline is an oil product which I was always told not to use on rubber hoses. I use a little dishsoap w/water to make the receiving piece and hose inside slick. JMHO. I assume your patented method has worked for years. To each his own.
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It's hot and humid in SW Ohio; been raining for several days and the ground is soggy w/more rain predicted all week. The reservior was up 4' 2 days ago and brimming w/trash. TD hot to boat."
 
"It's 4 hrs. by car across

"It's 4 hrs. by car across the state in SW direction. Also 30 miles north of Cincinnati or the intersection of OH, IN & KY."
 
GUY

I am not sure soaking a

GUY

I am not sure soaking a merc replacememnt hose will work.never tried it. I did not have the luxury of having a stove to boil water in the service bay I worked out of.........Would have been nice for fresh coffee all day though!

Those hoses are damn heavy duty and reinforced. I have had to "beat" them pretty good to get them to soften up.

They are not like the larger hoses inside the engine compartment.

As far as a slippery coating for the inside of the hose I really doubt a little vasoline or anything else will affect it much or not nearly as much as some brackish water the outside diameter comes in contact with...

But the use of dishsoap is a good one as it is a surfactent. (reduces surface tension)

Rain Rain Rain thats all we have been getting here!!
Heading up to laconia for the end of bike week and most likely spending it inside drinking as they are predicting RAIN all weekend!!!

My boat is still in shrinkwrap!
 
"still in shrinkwrap!"

"still in shrinkwrap!"

Dang! Are you waiting for the 4th of July? Or just working too much? Get thee to the water!
 
"Absolutley crappy weather,

"Absolutley crappy weather,

OH I also have a motorcycle that is WAY cheaper to operate and get 45 mpg and chicks dig it!"
 
Ghost thats a good one "ch

Ghost thats a good one "chicks dig it!" but with a boat. there in a bikini when there cruisin with ya. hope the weather clears up for ya

steve
 
"Dont worrie about that

I g

"Dont worrie about that

I got a tank full of fuel waiting that I purchased at $1.75 per gal last november. Got 3 or 4 hotties from the local watering hole (bartenders) that are dying to get out for a long fun booze cruz. They are all under 30...........
biggrin.gif
so it could get interesting, I hope........"
 
"Did the boiling hot water a f

"Did the boiling hot water a few times and it works, a product called "Power-Tune" works too.A way to test the water system with the lower unit off is to cap the hose at the therm housing and attach a hose to the copper tube and turn the water on, should be no leakage"
 
"Special thanks to Bt Doctur,

"Special thanks to Bt Doctur, Kghost and Guy Gaspar.
Problem is fixed and running cool as a cucumber. First of all major difference in original equipment Merc hose. A tough job but no kinks in that new hose. I did the boiling water thing but still went on hard even with the soap.
I'm ashamed to say but I found that base gasket on upside down. Duh! Talk about lessons learned.
I'm in the car repair business so I was buying parts from NAPA at my dealer cost to save money. Never again!

Kghost, good luck on that upcoming booze cruz with hotties.

Thank you all for your help

Brian"
 
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