78 Johnson 115 starboard cylinder head getting hot

[phx5kegsman]

Hello, getting ready for summer. Ran motor on muffs. steady stream coming from telltale. Then stream started spitting (not steady). IR thermometer showed 118F port side cylinder head and and 152F on starboard cylinder head. No change in RPM's or engine sound, although, it was idling a bit high. I immediately shot off the motor. Next day I drained and removed the lower unit. I took it to my garage and put it in holding fixture. I noticed that there was water all over the top of the lower unit. At this point, I had not even loosened the impeller cover bolts yet. I don't think water came in from the mating surfaces of the exhaust housing and lower unit. I had a new impeller laying around so I put it in. I did not have a new cover so I used the old one. I did have a new gasket. Today I put the muffs back on and the same thing happened. Steady stream from telltale at first then spitting and spurting water out. The hose was on about half way. Port side temp was 120F starboard side was 162F. I have not dropped the lower unit, yet.
Any Ideas?? I really don't want to try to remove the heads. I just know, because of it's age, that broken bolts would be very likely. TIA!

 

[racerone]

The water from the telltale does not go through the block.------look for / replace diverters.---or blown head gasket.------Head must come off.

 

[Crosbyman]

if you do not wish to pull the cyl head from fear of damaged bolts have you considered some products like rid-lyme etc... maybe you can flush out some accumulated crud.
see utubes. or work slow on the bolts !

check lower cyl head hose for clogs

 

[saltchuckmatt]

Salt water motor, yes or no?

If not, mud dobbers area or other nesting bugs?

Have you been praying to the outboards gods?

Many things to soak it in before removing the head.

 

[phx5kegsman]

Fresh water only. The intake screen has been bad since I've had the motor (about 5yrs). No mud Dobbers, but I have a 3ft jumper hose attached to my muffs. I suppose there could've been a "nesting bug". Before I attempt to pull the head, I'm going to pull the T-stats to check their condition, even though they're only 2-3yrs old. Maybe shoot some water through the hose. I'm sure that I will, ultimately, have to pull the head. I've gone through just about everything else on this motor but the heads and crankcase. Any tips on how to avoid breaking bolts? Any "secret sauce" to soak it with? Torch? It will take a few days for the parts that I ordered to arrive , so there's time to rep it!
TIA

 

[racerone]

Bolts usually come out easy on fresh water motors.

 

[phx5kegsman]

Crosbyman, I just watched the video and it's the exact symptoms I'm having. Same motor, too! Thank You

 

[saltchuckmatt]

Fresh water only. The intake screen has been bad since I've had the motor (about 5yrs). No mud Dobbers, but I have a 3ft jumper hose attached to my muffs. I suppose there could've been a "nesting bug". Before I attempt to pull the head, I'm going to pull the T-stats to check their condition, even though they're only 2-3yrs old. Maybe shoot some water through the hose. I'm sure that I will, ultimately, have to pull the head. I've gone through just about everything else on this motor but the heads and crankcase. Any tips on how to avoid breaking bolts? Any "secret sauce" to soak it with? Torch? It will take a few days for the parts that I ordered to arrive , so there's time to rep it!
TIA

How did the old impeller look when you replaced it? Any missing pieces? Small orifice's everywhere.

Could be the stats but not likely.

Racer is correct most likely on diverters and or examination.

Slighten tighten first and then try loosing. I have torque spec fingers knowing when they will break. If they turn then just keep going...if not, report back.

Self resurfacing the head is inexpensive and easy so many here can teach you that.

Reverse flush, examine and maybe you get lucky. Spiting out the tell tale is troubling as that stream does not go through the outboard or T-stat area.

Racer is the best at knowing these older motors and how the water circulates through.

Praying for you.

 

[phx5kegsman]

I pulled the Thermostats and there was something stuck in the port side t-stat, holding it open slightly. Looked like a piece of white plastic from the intake screen. I have a new one coming with the new thermostats.
As to your question about the old impeller. It really didn't look too bad. Not broken. But when I unbolted an removed the cover the impeller came off with it. I will check it closer tomorrow. I won't have much time to work on it until this weekend. So, I should probably order some gaskets.
Thanks

 

[saltchuckmatt]

I pulled the Thermostats and there was something stuck in the port side t-stat, holding it open slightly. Looked like a piece of white plastic from the intake screen. I have a new one coming with the new thermostats.
As to your question about the old impeller. It really didn't look too bad. Not broken. But when I unbolted an removed the cover the impeller came off with it. I will check it closer tomorrow. I won't have much time to work on it until this weekend. So, I should probably order some gaskets.
Thanks

Do you mean it stayed in the cup?
You would easily see missing pieces.

Well for now let's hope you've found your "smoking gun"!

 

[Crosbyman]

Mat..??? would a stuck open thermostat cause an overheat ?

 

[racerone]

One side is much cooler than the other.-----Has overheat buzzer sounded?

 

[saltchuckmatt]

Mat..??? would a stuck open thermostat cause an overheat ?

A partially plugged thermostat could be problematic yes, open or not. Doesn't affect the tell tale so yes there is a high percent the problem is still lurking.

Always frustrating.

 

[phx5kegsman]

The impeller was stuck in the cup, but it was not missing any pieces. The key was in the keyway.
Port side (the side w/stuck open thermostat) was 118F and starboard was 152F. I only ran it for maybe 90 seconds and shut it down.
I pulled the thermostats, relief valves, springs, etc. Replacements are on the way. New gaskets and water pump kit won't be in til next week. My engine is painted white. Not sure if it's factory or not. Is there any benefit to removing the paint around the bolts and hitting them with some PB Blaster or Liquid Wrench or something?
One of you mentioned that the water doesn't flow through the heads to get to the tell tale. Does it go through the exhaust cover?

 

[phx5kegsman]

I also think that the problem "still lurks"

 

[saltchuckmatt]

The impeller was stuck in the cup, but it was not missing any pieces. The key was in the keyway.
Port side (the side w/stuck open thermostat) was 118F and starboard was 152F. I only ran it for maybe 90 seconds and shut it down.
I pulled the thermostats, relief valves, springs, etc. Replacements are on the way. New gaskets and water pump kit won't be in til next week. My engine is painted white. Not sure if it's factory or not. Is there any benefit to removing the paint around the bolts and hitting them with some PB Blaster or Liquid Wrench or something?
One of you mentioned that the water doesn't flow through the heads to get to the tell tale. Does it go through the exhaust cover?

Just blow some water through all those rubber hoses, try to reverse flush and put it all back together and test. 152° is not reached overheat yet but was probably going to. Has any of the paint yellowed on the head or around the block area? That might indicate that it had been overheated that one time.

I had a older johnson 90 horse when I was about 20 years old that when I reversed flushed through those pipes or hoses out shot a hunk of salt that you'd never believed could go through there. Doesn't take much to block off an orifice... at the same time sometimes you get lucky and blast them free. That tough old motor sank in Puget Sound which is salt water and my ex Evinrude dealer uncle sprayed water down the spark plug holes and got it running in 20 minutes. That boat ran for many many more years and other than a few electrical issues from the saltwater, I sold it running for all I know it's still running to this day. It was on an 18 foot Fiberform made in Spokane Washington. I was sold on Evinrude Johnson probably when I was about 6 years old and that's all I've really known. Otherwise just pull the heads and pull the exhaust cover... it's not that big a deal.

 

[racerone]

152F is not overheating.---Tested the overheat horn?

 

[phx5kegsman]

The new remote that I installed a few years ago came with a new horn. The horn works and so do the heat switches. I know 152 isn't overheating, but it's kinda hot for 90 seconds running. Although, the warmup lever was up all the way. What got my attention was the tell tale sputtering. Never had that problem before.
When you backflushed through the hose where did the chunk come out from?

 

[phx5kegsman]

That may not have made sense. I meant : where did the chunk of salt exit the motor when you backflushed through the hose?

 

[saltchuckmatt]

That may not have made sense. I meant : where did the chunk of salt exit the motor when you backflushed through the hose?

I was in my 20's and now I'm 62...I'm lucky when I can find my socks!

Sorry.