Sneakin feeling somethings plugged 70hp Johnson cooling issue

[MoparMMatt]

I noticed that the water intake screens were damaged the last time I took out our 1974 70hp Johnson (stinger), and by the time I got it on the trailer the tell tale was down to a trickle. I figured the motor was due for a new water pump at a minimum. When I put it all back together I could not get water to cycle through the top of the motor. Here is the rub:facepalm:, did I
A: turn the fins the wrong way in the pump cup... possibly causing the impeller to not be able to pump water correctly?
or
B: do I have a plugged cooling system?

Having a new handy dandy (part# 506897) service manual im relatively certain I put the new pump together correctly. Any guesses? And are there any troubleshooting methods to narrow it down.

 

[Daviet]

Re: Sneakin feeling somethings plugged 70hp Johnson cooling issue

Welcome to the forum.
A: It really doesn't matter, as soon as the engine starts the vanes on the impeller will flip to the proper direction.
B: Does the engine actually overheat, have you checked the tell-tale to see if it is plugged, happens quite often.

 

[MoparMMatt]

Re: Sneakin feeling somethings plugged 70hp Johnson cooling issue

thanks for the welcome.

As for checking the tell tale, I pulled it from the head and blew on the line, it shoved out some residual water so it is not plugged, as for over heating, I only ran it for a minute. I had the top off so I could look for other issues, and there was a good amount of heat on the flat head next to the carbs. I didn't leave it run any longer than that, fearing it would get hot. I also ran it through a little RPM and put it in gear, ran some RPM, still no water out of the water check / tail tale.

 

[Daviet]

Re: Sneakin feeling somethings plugged 70hp Johnson cooling issue

You checked the hose, but what about the fitting on the block, is it clear?
I think you are talking about the exhaust cover, it will get hotter than the rest of the block.
Are you running it on a hose or in the water?

 

[MoparMMatt]

Re: Sneakin feeling somethings plugged 70hp Johnson cooling issue

provided that tube was coming off an 90 degree elbow at a glance it did not appear to have any visible obstructions, BUT I will run a pipe cleaner (yes they do still make those) through it in 5 minutes and will let you know if anything showed up.
I am using muffs to induce the water to the system. On side note, water is coming out of every other pea sized opening to the side and rear of the lower unit.

 

[Daviet]

Re: Sneakin feeling somethings plugged 70hp Johnson cooling issue

I use a piece of weed wacker line to check the hose and fitting.
If you are running it on a hose, unless there is blockage or the thermostat is stuck closed, the engine should not overheat. The water pressure will actually mask a bad water pump.

 

[MoparMMatt]

Re: Sneakin feeling somethings plugged 70hp Johnson cooling issue

provided that tube was coming off an 90 degree elbow at a glance it did not appear to have any visible obstructions, BUT I will run a pipe cleaner (yes they do still make those) through it in 5 minutes and will let you know if anything showed up.
I am using muffs to induce the water to the system. On side note, water is coming out of every other pea sized opening to the side and rear of the lower unit.

update: I did check and see if the tube and the elbow were plugged. they were not, I did however manage to break the little plastic elbow that plugs into the exhaust cover. Its made out of plastic... PLASTIC. time for a trip to the parts store.

 

[MoparMMatt]

Re: Sneakin feeling somethings plugged 70hp Johnson cooling issue

where would a blockage most probably be? and should I pull the thermostat and try to run it, will that open the water flow to the tell tale? because water still is not coming out of there.

 

[iwombat]

Re: Sneakin feeling somethings plugged 70hp Johnson cooling issue

It's plastic for a reason. A nice bronze one would cause electrolysis and eat away at the threads.

 

[MoparMMatt]

Re: Sneakin feeling somethings plugged 70hp Johnson cooling issue

I think im going to pull the thermostat

 

[MoparMMatt]

Re: Sneakin feeling somethings plugged 70hp Johnson cooling issue

It's plastic for a reason. A nice bronze one would cause electrolysis and eat away at the threads.

what is that little piece called? I don't know what to ask for or search for on the net.

And I pulled the thermostat, and flushed out the two little holes that had plastic plugs in them, a big chunk of white plastic came out, the thermostat was also packed shut. I also pulled the lower unit and blew water up that copper tube, all kinds of crap and sand came out of the open hole where I took out the plastic elbow leading to the tell tale. Married lower unit to power head.,I started the motor up with the exposed hole that the plastic elbow goes in still wide open with thermostat out. At last, water came pouring out of it when I fired it up. I plan to tank test it after I get the little elbow. I would hazard to say its fixed. Now I just need to determine if the thermostat is good, replace the gasket, replace the elbow, and tank test it. Am I missing something?

 

[iwombat]

Re: Sneakin feeling somethings plugged 70hp Johnson cooling issue

I wrote up an article on adding an indicator to older motors. It's got the part # in it. I'll go find it.

Edit: Ok here's the write up (http://forums.iboats.com/engine-fre...johnson-evinrude-adding-tell-tale-222677.html)

Indicator Elbow OEM part#321886 or Sierra #18-3290


Just replace the t-stat. You have it out already.

 

[MoparMMatt]

Re: Sneakin feeling somethings plugged 70hp Johnson cooling issue

I wrote up an article on adding an indicator to older motors. It's got the part # in it. I'll go find it.

Edit: Ok here's the write up (http://forums.iboats.com/engine-fre...johnson-evinrude-adding-tell-tale-222677.html)


Indicator Elbow OEM part#321886 or Sierra #18-3290


Just replace the t-stat. You have it out already.

thanks for the part number. My motor already has a indicator on it. I will however re-route it over the block. thanks again, this saves much hair pullin out.

 

[kd4gij]

Re: Sneakin feeling somethings plugged 70hp Johnson cooling issue

I wrote up an article on adding an indicator to older motors. It's got the part # in it. I'll go find it.

Edit: Ok here's the write up (http://forums.iboats.com/engine-fre...johnson-evinrude-adding-tell-tale-222677.html)

Indicator Elbow OEM part#321886 or Sierra #18-3290


Just replace the t-stat. You have it out already.

Hi I just read your write up. I have an 1982 70 hp evinrude. Where is the best place to relocate the tell tale.

 

[kd4gij]

Re: Sneakin feeling somethings plugged 70hp Johnson cooling issue

double post

 

[MoparMMatt]

Re: Sneakin feeling somethings plugged 70hp Johnson cooling issue

MOD please close thread. Problem solved.

 

[phillnjack2]

Re: Sneakin feeling somethings plugged 70hp Johnson cooling issue

errr no its not finished just yet.

the elbow you broke was on the side of the exhaust cover, now you realy should be looking into plugging that and having the tell tale come from top of engine block !!!
this is a update that should of been done ages ago,its to stop any air getting trapped and not letting the engine coll correctly.

just because the tell tale looks good means nothing, that just shows water is getting to the point of the plastic fitting.
It DOES NOT show water is getting to the cylinder head to keep it cool !!!!!!!!.

Now lots of people also think a very high pressure tell tale means its great, this is not so.
a high pressure tell tale could mean a blockage further up the chain of the cooling system causing high pressure build up in the tell tale.

with the thermostat out of the engine I would run it up in a water butt with some salt away in the water butt and let it run for an hour or so.
this will help clean out all the water ways of any lime scale or salt build up.
when you have finished then put it the new thermostat and gasket and run it on the muffs for a couple of mins just to be sure the thermostat is opening ok and take note of the tel-tale pressure /amount etc.
this will give you a good guide for future reference to see how much water comes out when the engine is clean of all the crap in the water passage ways.

so no, your not finished just yet ha ha ha


phill