1980 johnson V4 overheating

S

straubz

Recruit

Joined

Mar 22, 2011

Messages

4

• Mar 22, 2011

• #1

This motor starts easy enough but overheats in a matter of minutes.
I dropped the leg and flushed the water channels backwards with good flow coming out the water input tube.
I replaced the impeller whilst the leg was off (nothing wrong with the original either)
I get a very strong stream from the telltale so i assume the water cooling system is fine.
Ive noticed that the right hand heads are too hot to touch but the left side are not too bad.
Ive researched a bit but no one answer stands out.
At a loss and any suggestions before taking to a boat mechanic would be appreciated

 

DargelJohn

Petty Officer 1st Class

Joined

Feb 14, 2010

Messages

337

• Mar 22, 2011

• #2

Re: 1980 johnson V4 overheating

I've had the same issue on a '96 Johnson 88SPL. Right side overheats and the left is too cool. After pulling the thermostats more times than I care to mention, I think I have stumbled upon the solution. The little radiator hoses that go to either bank, the one on the right was slightly kinked. I shorten that hose about an 1/8" which took out the kink. Knock on wood, it has stopped over heating.

 

B

boobie

Supreme Mariner

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Nov 5, 2009

Messages

20,826

• Mar 22, 2011

• #3

Re: 1980 johnson V4 overheating

I know this is really a dumb question, but are you getting overheat alarms when this happens ??

 

S

straubz

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Mar 22, 2011

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4

• Mar 23, 2011

• #4

Re: 1980 johnson V4 overheating

boobie said:

I know this is really a dumb question, but are you getting overheat alarms when this happens ??

Click to expand...

Yes the alarm sounds after 5 minutes and i shut down.

An update on this matter, i pulled the thermostat cover off to check for faults there only to find there was in fact no thermostats in place. (the centers had been removed)

 

B

boobie

Supreme Mariner

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Nov 5, 2009

Messages

20,826

• Mar 23, 2011

• #5

Re: 1980 johnson V4 overheating

You also could have some swelled up water deflectors in the block or possibly a blown head gasket.

 

E

emdsapmgr

Supreme Mariner

Joined

Dec 9, 2005

Messages

11,551

• Mar 24, 2011

• #6

Re: 1980 johnson V4 overheating

Boobie has some good comments. If you find any blockages around the cylinders when you have the head off, you also may want to pull the head covers off and look for similar blockages.

 

S

straubz

Recruit

Joined

Mar 22, 2011

Messages

4

• Mar 27, 2011

• #7

Re: 1980 johnson V4 overheating

Ok I think ive found the problem. The water deflector in the right hand cylinder head had a lot of debris beside it so im assuming this was enough to create a blockage and overheat
This was after installing a new thermostat kit, cleaning water channels in exhaust jacket and head covers, and replacing swollen gaskets.
Im going to check the left hand head to make sure its all good,
Does anyone know the torque settings for my engine as its not stated in the manual

Cheers

 

D

daselbee

Commander

Joined

Jan 20, 2009

Messages

2,765

• Mar 27, 2011

• #8

Re: 1980 johnson V4 overheating

Cylinder head bolts are 216 to 240 INCH-lbs.
Head cover bolts are 60 to 80 in-lbs.

 

S

straubz

Recruit

Joined

Mar 22, 2011

Messages

4

• Mar 28, 2011

• #9

Re: 1980 johnson V4 overheating

Just removed the left cylinder head and found this blockage at the deflector.

Cheers for the advice.

 

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C

catchnrelease

Recruit

Joined

Mar 30, 2011

Messages

2

• Mar 30, 2011

• #10

Re: 1980 johnson V4 overheating

I'm getting the same problem on my johnson 70. After unpluging the pisser I still get an alarm after about 5 minutes. It's an intermitent beep. I cleaned some wasp nests throught out the engine from sitting all winter. Where else could debree be??

Also what shold the water pressure be reading I am close to zero right now.