HOT HOT,HOT!! Temperature gun, good thing.

[jerryjerry05]

Working on my neighbors 6hp 1974Johnson
​Cleanest 6 I've seen especially for the age.
​The deal is I keep the motor running he supplies the boat 12ft. alum. (about the same age),and we fish his Grouper
​and Flounder spots.

The owners son was working on it and it stopped pumping water.(guide tube alignment wrong)

​The owner ask me to check it out.
​I get it runnin and pumpin.
I get my heat gun out to check the temp.
​It's runnin pretty warm, not HOT but too warm.
I pull the thermo and it's fairly corroded.
Clean it up and run it again.
Runnin cooler but the heat gun says there's a HOT spot between the cyl.
It's at 170d I think the thermo is about 140d.

​The heat gun says there's a hot spot that needs attention.
​I pull the head and sure enough the passages are clogged in the hot zone.

Without the heat gun I would never had found the clog.
You can see on the first pic where the clog on the left of the head is.
I spent 15$ on Amazon a few years ago and it's helped me a few times.

I figure it's saved this motor.

 

[Grub54891]

Nice catch! I use the infrared temp gun quite a lot, It does help when diagnosing a lot of different things. Even last winter I used it around the house looking for cold/drafty spots. Saved a lot on the heat bills!

 

[Tnstratofam]

Nice catch indeed. An infrared thermometer is good tool to have in ones tool box for sure, and there are some good useable inexpensive models out there.

 

[Sea Rider]

OB's water paths will always clogg with salt no matter if OB is flushed conveniently after each use. Are heat/cold cycles that collects mini salt layers one in top of the other inside water paths. Head gaskets are not eternal, should be replaced at around 300 worked hours while taking advantage to clean all internal water paths to immaculate clean cond. OB will cool as a champ.



One part that's always overlooked when changing head gasket is not opening exhaust cover to cleaning internal exhaust water path, being a hotter area usually collects more salt as in this pic than the rest of the powerhead. Have a look on that 6 HP...Install a new thermostat & related powerhead gaskets to work properly with all cleaned internal water paths...

Happy Boating

 

[oldboat1]

sure don't miss the salt water, at least for outboard repair. The passages under the exhaust cover can also be a problem, although probably not worth checking if you have it running at a proper temp. (potential for broken bolts).

I'm also a big fan of IR guns. They can also help in locating corrosion or shorts in wiring.

 

[Sea Rider]

The passages under the exhaust cover can also be a problem, although probably not worth checking if you have it running at a proper temp. (potential for broken bolts).

As an illustration, the posted pic corresponds to a portable OB which has been properly flushed on muffs with fresh water for at least 10 minutes while OB was ON running geared at fast idle speed soon after returned from its outing. If you clean all cylinder head water paths it's a crime not to clean the internal exhaust water passage, bear in mind that pistons works adjacent to that hot area and any severe heat up building there will discolor pistons which is no bueno for them LOL!!

Breaking bolts while removing covers, cylinder head or even a thermo cover is something you will have to deal with, much worse if OB runs on salt water and is never flushed soon afterwords which is a must do if wanting to have your beloved OB in near mint internal clean condition while cooling spot on.

OB's are not car engines running with the green krypto stuff inside them, All OB water passages should receive full maintenance not partial ones...

Happy Boating

 

[Sea Rider]

This pic will surely cheer U up to clean mentioned exhaust water passage. Most OB's have internal anodes on that area, this is a recurrent salt clog area on this OB.




As you can see there's a huge salt deposit on top anode which is limiting extensively water passing by at internal passage to cool properly that hot area. Second pic corresponds to same OB mentioned on first post without anode removed as in first pic, so draw your own conclusions.

Happy Boating

 

[shaw520]

Sea Rider,.. thats quite convincing,....aprox how many hrs of service to get to this point ?

 

[Sea Rider]

This is a 2 year oldie all year round used OB with 600 metered worked hours and flushed to insane perfection. Will find this sort of thing on all OB's till they don't run with the green krypto stuff, expect to find larger salt formations on larger OB's.. Salt Away product should do it's homework right when applied on new OB's from time to time.

Were about to tear down a low use 150 HP pandora box powerhead that has never been flushed, don't want to imagine all the salt layers and crusts that will be found inside. LOL!!

Happy Boating

 

[shaw520]

Show us ! :cheerful:

 

[gm280]

Infrared Red LASER guns are pretty good, and I have and use one. But if I could afford it, I would like to have a FLIR camera. It would show hot spots instantly. But I can't verify the cost for the usage.