johnson jw-17 water pump question

[does52]

I finally got my jw-17 3 hp outboard running.  it has been sitting in my shop for the last 40 years.  How can i tell that the water pump is cooling

the engine?  I checked impeller and it seems to be ok. Want to make sure i do not overheat engine.  thanks

[Mumbles]

If the impeller is 40 years old, it should be replaced no matter how good it looks. After sitting for that long, it will only be a matter of time before it falls apart and you probably wont notice the motor overheating because of it.

These three horse motors have the water outlet incorporated into the idle relief port on the front of the exhaust housing and it is covered by a small plate. It’s hard to see the water coming out as it can be a spray or a dribble. The best thing to do would be to replace the impeller as part of a preventive maintenance program and invest in a cheap infrared thermometer. The IRT can be used to scan the running motor while the lower cover is removed.     

• This reply was modified 3 years, 4 months ago by Mumbles.
• This reply was modified 3 years, 4 months ago by Mumbles.
• This reply was modified 3 years, 4 months ago by Mumbles.

[does52]

Thanks for the advice.  I am getting a new impeller and a IRT. One more question.  What temp range should this engine operate at?  Thanks again!

[frankr]

You can find temps all over the scale, depending on where you check.  Exhaust cover plate and right around spark plugs are the hottest because they are not directly water cooled. Also, lake water temp and engine speed are big factors.

[fleetwin]

Like Frank says, these engines can be tough to check cooling wise because they run at very different temperatures depending on where you check.  The exhaust cover and head will be pretty warm/hot for the reasons Frank mentioned.  Usually, the temp is checked on the starboard side of the block near the ID core plug.  The engine shouldn’t get hotter than 165F at this point.

There should be a very fine spray of water/mist being expelled from the area that Mumbles pointed out.

[does52]

Thanks for the good advice.  I installed the new impeller and ran motor.  I checked temps with IRT and all temps were fine.  thanks again.  The only thing i need now is to find a front handle.

[Steve A W]

I don’t know if he is selling parts anymore but try Doug Penn.

 

Member of the MOB chapter.
I live in Northwest Indiana

[DAN UMBARGER]

Steve A W wrote:

I don’t know if he is selling parts anymore but try Doug Penn.

 

Yes…he and his son Matt sell parts…I’ve purchased several parts lately from him….nice people to do business with. His email addy is theoldoutboard@gmail.com and his Ebay name is mixersix.

[does52]

Took the motor out for test run and some fishing.  ran great at low speed and after some high speed adjusting ran as good as it did 45 years ago!!  thanks for the help.!!

[crosbyman]

Great news … another one saved from the pile…:-)

Joining AOMCI has priviledges 🙂

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