1985 235 overheat problem, need some help guys

[SpecialAgentGibbs]

!985 235 Johnson, having an overheat problem:
Strbd head goes to 210-215 on a non-contact temp gun (immediately shut it down).
1) new T-Stats & bypass valves.
2) removed water plates (on heads), passages all clean & clear.
3) excellent pisser hose flow.
4) new water pump kit.
5) carbs rebuilt.
6) fresh, clean fuel (pre-mix, 50:1)

Have large amount of water coming out between leg & lower unit so, removed lower unit.
Connected water hose to the water tube going up to the power head, and get lots of water coming down out of the leg cavity that the water tube goes up through. Water tube seems to be solidly inserted into the bottom of the power head.

Water tube is not damaged or rotted.
What gives???
I would really like to get this solved, and go boating

 

[SpecialAgentGibbs]

Re: 1985 235 overheat problem, need some help guys

Just curious, is this repairable or am I wasting my time with this motor???

 

[phillnjack2]

Re: 1985 235 overheat problem, need some help guys

Now first of all the water jackets around the heads could be blocked with salt or limescale.
the rubber diverters if this engine has them could of moved or be blocking the right path.

when running at idle then revved up quick does water come out of the top exhaust holes ?
Have you got plenty of oil in the fuel ?
is the timing right ?
did this just suddenly happen ?
or did you get it like this ?

the cavity between powerhead and mid section could be blocked with salt or limescale or
could be leaking due to bad gasket ?

with hose running up the pipe to powerhead is water getting to the thermostats ?

But sounds to me like a blockage in the head if only happening on one side.
There is a plate on the top between heads, take that plate off and inspect that area for blockage !!!!!!!!
see what happens there with hose running up the tube ,dont even need it running to check this.

if you can get a kettle of boiling water with some descaler in it,then pour it into the head that gets hot.
if this helps a bit then you know the head waterways need a proper clean out.

when engines are just flushed with a hose from the tap,if that area has hard water then limescale builds up, just look
in a kettle and you see it dont take long.

stuff like salt-away and other cleaners can be good if the regime is kept up from new or a recently cleaned out (manualy) engine.


and if it was running good then ofcourse its worth doing.

its not always a case of not getting enough water,
its often the case of the water in that head not getting out !!!!
thus no cooler water gets in to cool it down to right temp !!!!this happened to my friends v4.

all this is just a few thoughts ive had, might not be any of the above, but maybe worth chcking and will not
cost anything but time to try


phill

 

[SpecialAgentGibbs]

Re: 1985 235 overheat problem, need some help guys

What I see being an issue, is that with a hose hooked directly to the water tube going to the power head, water is coming back down from the powerhead around the water tube/shaft cavity (lots of water).
It sure seems to me that water should not be coming from there.
Timing has been checked, and in spec.
As stated above, 50:1 oil/fuel mix (completely NEW fuel system, tank to carbs, and carbs rebuilt with all new jets, etc.)

I just got this boat, and it had not run in years apparently.
Water plates on the heads were removed, inside there was all clear.
Voltage regulator also removed, nothing more than surface corrosion in there, no buildup.

 

[phillnjack2]

Re: 1985 235 overheat problem, need some help guys

Ok first of all.could very easily be the top seal of the water tube gone bad or pin holes in it !!!!!!!!!!
when you put a hose on the pipe to go upto powerhead, if all things were working good then water would be
flowing back into mid section.
the water goes up the pipe round the engine block then back down into the mid section/exhaust ..
the tell tale is from exhaust area not from after the cooling of the engine has taken place !!
with the hose on the pipe going up to the powerhead you should get tell tale even without it running !!!!!!!!!!!!!

now with a hosepipe on the lower tube just undo the thermostats and see if water is getting up there.
if so then so far so good.

if the gearbox was fitted and for example you could get water up the pipe , when engine runs you could and should see it comming out of the centre of the prop, this is called thru hub exhaust, also by the two holes underthe hood at the back,these are about 3/4 inch dieameter.
you see the exhaust gets mixed with water that has been used to cool the engine.

so getting water comming back down could mean
A the thermostats are not closing or
B the relief is not working or
C this is the exhaust overflow.

when the hose was on the tube did any water come from the tell tale ?
if this has a tell tale and no water came from it then you have a blockage, and its probably at the top of the engine or
under the powerhead between engine block and mid section.
i would definitely check out the top plate right up by the engine lifting eye behind flywheel.
this can get realy blocked up

 

[SpecialAgentGibbs]

Re: 1985 235 overheat problem, need some help guys

Ok first of all.could very easily be the top seal of the water tube gone bad or pin holes in it !!!!!!!!!!
when you put a hose on the pipe to go upto powerhead, if all things were working good then water would be
flowing back into mid section.
the water goes up the pipe round the engine block then back down into the mid section/exhaust ..
the tell tale is from exhaust area not from after the cooling of the engine has taken place !!
with the hose on the pipe going up to the powerhead you should get tell tale even without it running !!!!!!!!!!!!!

now with a hosepipe on the lower tube just undo the thermostats and see if water is getting up there.
if so then so far so good.

if the gearbox was fitted and for example you could get water up the pipe , when engine runs you could and should see it comming out of the centre of the prop, this is called thru hub exhaust, also by the two holes underthe hood at the back,these are about 3/4 inch dieameter.
you see the exhaust gets mixed with water that has been used to cool the engine.

so getting water comming back down could mean
A the thermostats are not closing or
B the relief is not working or
C this is the exhaust overflow.

when the hose was on the tube did any water come from the tell tale ?
if this has a tell tale and no water came from it then you have a blockage, and its probably at the top of the engine or
under the powerhead between engine block and mid section.
i would definitely check out the top plate right up by the engine lifting eye behind flywheel.
this can get realy blocked up

Perhaps I'm not being clear enough in my description.
1) New thermostats.
2) New bypass valves (reliefs).
3) Pisser hose has excellent flow (telltale).

Yes, I am quite aware that water exits through the exhaust/prop.
With the lower unit off, and a hose connected to the water tube, I am getting LOTS of water coming back down through the center of the leg, where the water tube and drive shaft go, this in NOT the same as the exhaust cavity.

 

[emdsapmgr]

Re: 1985 235 overheat problem, need some help guys

I am not sure from your description, but you may have meant that you pulled the head covers off the heads, and that they were clear. If that's what you did, that's a solid inspection. You have not yet said that you removed the heads, esp the starboard one. You need check the rubber water deflectors/diverters. These can get misshapen, migrate out of location, and even accumulate debris-any of which will slow water flow around the cylinders and through a head. Certainly any one of them can cause an overheat. I'll attach a picture which shows how one is correctly placed. One per cylinder.

 

[SpecialAgentGibbs]

Re: 1985 235 overheat problem, need some help guys

HOW COULD WATER COME OUT OF THE BOTTOM OF THE ENGINE BLOCK (except for the exhaust), WHERE IT'S SUPPOSED TO BE GOING IN???
IF THE WATER IS NOT GOING UP, INTO THE ENGINE, OF COURSE IT'S GOING TO OVERHEAT RIGHT?

 

[phillnjack2]

Re: 1985 235 overheat problem, need some help guys

Well you obviously dont understand what we are saying.
some water goes to the engine cylinders and some goes straight to the exhaust housing.
but it dont get mixed at the exhaust housing,its way after that it gets mixed in with the exhaust.
and some also just gets chucked out elsewhere.
now if you dont believe it comes out from other places apart from the exhaust,then please tell me what the other holes in your gearcase are for ? at the front there is one for starters, and what about the water that comes out above the lower engine mounts ?
where does that come from then ?

look at videos of engines running on muffs and you will see water comming out of various places. not just the exhaust.
this link below is a poor quality video, but you can see whater comming out the prop comming from 2 top exhaust holes, and
from the FRONT OF THE GEARBOX !!!! this mid section will be full of water.it dont all just come from exhaust.
1979 Evinrude 235 outboard for sale - YouTube

Now if you have not got a clear path on the left or right cylinder head then the pressure will show more on the tell tale and
will also chuck more water out the engine relief holes.
when the water pump is running the pressure dont just keep on building or it would be busting seals, it gets diverted.
I will take a close up vid of my engine to show it running on muffs and post that once i video it.
youl then see there is a few places it comes out of (providing not bunged up with crud ).

take the thermostat cover off the offending side and see if water pumps up to that ?


phill

 

[clanton]

Re: 1985 235 overheat problem, need some help guys

Remove the cylinder heads, replace the water deflectors. Port and strb sides.