1979 35 hp Johnson stalling/runing problems

[Kearnal]

Hi, I've got a 1979 35 hp Johnson that has been running very poorly. It is very hard to start and won't idle at a normal rpm, only at a high rpm. As soon as you try shifting, it immediately stalls.

Occasionally you can start the engine in forward, but it doesn't have nearly the same power as normal.

We pulled the spark plugs and noticed a milky white liquid which we suspect is water leaking into the cylinder.

Also we noticed that same milky water leaking out the bottom of the engine when its running in neutral.

One time when we tried starting it the pull cord locked up and was impossible to pull, then after pulling out the spark plugs it was possible to pull it again. My friend thinks that it was "hydro locked."


Things we've tried:


-Cleaning the carburetor
-Replacing the fuel pump
-Cleaning the connections on the coils
-Using fresh gas
-Cleaning the spark plugs


We haven't had any luck with any of that, does anybody have any ideas?

 

[Daviet]

Re: 1979 35 hp Johnson stalling/runing problems

If you have water leaking into the cylinders, you need to pull the head and check the head gasket.

 

[Kearnal]

Re: 1979 35 hp Johnson stalling/runing problems

I've never done that before, is it hard to do without messing anything up further?

 

[jasper60103]

Re: 1979 35 hp Johnson stalling/runing problems

I've never done that before, is it hard to do without messing anything up further?

Not a hard job, but I would get a OEM service manual for reference. Usually can find them cheap on ebay.
But before you pull the head, you may want to check/record your compression first, and post back with your results.

 

[Kearnal]

Re: 1979 35 hp Johnson stalling/runing problems

Alright so, we took apart the head...... and the gaskets looked pretty bad so we replaced the thermostat, the head gasket, and the one that goes on top (not sure the name.)


Started it up and it didn't seem to have any improvement, it was leaking out of first gasket so we tightened the bolts a little bit more and it stopped the leaking.

After a few minutes of running it seemed to fix the idle problem and I was able to shift into forward without it stalling.

We put the boat in the lake and drove it around and it seemed to be good as new.

Today we tried wakeskating behind the boat and it took a lot longer to pull up the rider than it normally does. It has a lot less power.


Sometimes the boat will make a, "sneezing type sound" I'm not sure if that is bad or if it has anything to do with this but I thought I would mention it.


Does anyone have any ideas why we lost power or what we should check?

 

[Daviet]

Re: 1979 35 hp Johnson stalling/runing problems

When you put the new gasket in, did you torque it to the proper spec and torque the bolts in the proper order?
Does the "sneeze" happen at an idle, do you have the low speed needle adjusted properly?

 

[Kearnal]

Re: 1979 35 hp Johnson stalling/runing problems

The "sneeze" happens at idle and we're pretty sure the low speed needle is set right. I'm pretty sure it was supposed to be at 1 and 1/4 turn.


We weren't sure what order to do the bolts so we just got them almost tight then tried to evenly tighten them down.