1976 85 johnson has oil leaking out of carb

[smitty_bb]

I have a 1976 85 hp Johnson that is smoking and all four plugs are keep getting soaked with oil, I also have oil/gas leaking out of the air breather. Does anyone out there know what kind of problem this it??

I am running a 50:1 oil/gas ratio. I am also experiencing power loss.

I am new to outboards, and any help would be greatly appreciated!

Thanks

 

[R.Johnson]

Re: 1976 85 johnson has oil leaking out of carb

On an engine this age you want to do the basic's, compression, ignition, fuel,

 

[ezeke]

Re: 1976 85 johnson has oil leaking out of carb

50:1 is correct. The motor will smoke far less if you use 100% synthetic TCW-3 oil, QL77JC4 Champion spark plugs and good thermostats. The motor should not be run at more than 15 degrees from the perpendicular.

The most likely reason for the oil at the carburetor is that the carburetors have not been rebuilt for some time or, that if they were, the float valves were not done correctly.

This is all theory, however, because without the results of your preliminary compression and spark tests, it's nothing but a WAG.

 

[smitty_bb]

Re: 1976 85 johnson has oil leaking out of carb

I replaced the spark plugs, which where QL77JC4 and I'm running Amsoil synthetic. Is where anyway it could be the coil packs, two of them have cracks in the tops of the?

 

[reload]

Re: 1976 85 johnson has oil leaking out of carb

Cracks in coils is not a good sign but I think the trouble is fuel related. As mentioned, floats could be set to high, maybe not seating. Jets may not be ajusted correctly. Chokes may be partialy closed.

 

[R.Johnson]

Re: 1976 85 johnson has oil leaking out of carb

Before we groom this dead horse, let's try a compression test. That engine is 30+ year's old.

 

[munro_capri]

Re: 1976 85 johnson has oil leaking out of carb

I have a 1975 85 hp rude, small cracks in on the coils, runs fine. I was also getting some oil/gas below carbs, just a couple of drips but more if the engine was tilted soon after a run, replace air in take gasket from infront of carbs and the hose just under the carbs from the power head to the in take was loose, replaced that.
I was also experiencing a little power loss, did a decarb with seafoam as suggested on this forum, helped a lot with power and smoking.
Check compression, spark then carbs if problem is excessive.

Not to steal thread but Ezeke you say not to run at more than 15 degrees, my motor does not have power trim and I have in shallow water put the motor up on the trailering arm, the lower end is in the water enough and the reves are kept to a minimum???? Is ok, I'm assuming the 15 degrees is to help stop the gas/oil from coming out of the carbs??

 

[smitty_bb]

Re: 1976 85 johnson has oil leaking out of carb

on a compression test, how much compression should I be looking for? Could the carbs be causing the oil on the plugs and the smoking by running to rich? Also the engine has a very rough idle, and is very hard to start the first time, but after it starts I can shut it down an it will right back up the first try.

Munro capri you mentioned "a decarb with seafoam " what is that and should I try it?

 

[ezeke]

Re: 1976 85 johnson has oil leaking out of carb

The de-carbon process is covered in the Engine FAQ forum here:​

http://forums.iboats.com/showthread.php?t=158076​

Your compression test should be done with all spark plugs out and engine warmed. Use a screw-in type tester. The compression readings should be within around 10% of each other.​

The actual readings will depend on the amount of wear on the rings and cylinders but are less significant than the range of values.​

Cold starting the 1973-1977 85HP depends on 100% fully closed choke plates and a battery capable of turning the engine at 300 RPM. The only way to assure that the chokes plates are fully closing is to look down the barrels while someone cranks the engine. 1/16 of an inch is not fully closed. Adjust by moving the solenoid in small increments.​

Your carburetors have all fixed jets which cannot be adjusted. If you are running lean or rich it is probably because the carburetors have not been cleaned and rebuilt recently.​

 

[smitty_bb]

Re: 1976 85 johnson has oil leaking out of carb

I did a compression test, three cylinders where at 125 psi and one was 115 psi. The boat sat up for about two years before I bought it, about 2 months ago do you think I might need a carb rebuild?

I tried starting it with the choke on and it started alot better, it looks like both choke plats close 100%. thanks for the tip!

 

[ezeke]

Re: 1976 85 johnson has oil leaking out of carb

Those compression numbers are good, but I would do two things: check them again in reverse order and do a full de-carbon treatment. The decarb might bring the 115 psi in line.

If you have the time to do them, I would recommend that the carburetors be rebuilt, but doing the job without the repair kits is a waste of time.

 

[smitty_bb]

Re: 1976 85 johnson has oil leaking out of carb

How do I do a de-carbon treatment? Is rebuilding these carbs somthing I need to take to a shop?

 

[ezeke]

Re: 1976 85 johnson has oil leaking out of carb

The de-carbon process is covered in the Engine FAQ forum here:


http://forums.iboats.com/showthread.php?t=158076​

 

[munro_capri]

Re: 1976 85 johnson has oil leaking out of carb

The hardest part of the decarb was finding Seafoam! CarQuest here in Southern Ontario carries it, I checked Napa and a few other places could order it but did not carry it.
Follow instructions that Ezeke posted, not tough to do, I also did the Deep Creep method first.
Idled smoother, a little less smoke and top end and hole shot seems better than before.

 

[burroak]

Re: 1976 85 johnson has oil leaking out of carb

I replaced the spark plugs, which where QL77JC4 and I'm running Amsoil synthetic. Is where anyway it could be the coil packs, two of them have cracks in the tops of the?

No.

Just mix up some epoxy and cover the cracks. They'll be fine.

 

[burroak]

Re: 1976 85 johnson has oil leaking out of carb

How do I do a de-carbon treatment? Is rebuilding these carbs somthing I need to take to a shop?

Probably not. Get the OEM repair manual and follow it. It's simply cleaning and parts replacement. Photographs as you disassemble it will be of great help. If you get stuck, come to iboats.

 

[smitty_bb]

Re: 1976 85 johnson has oil leaking out of carb

I couldn't find "Seafoam" but I got a "marine motor de-carb" made by Valvtect at a local marina, it comes in a spray can and is to be sprayed in the carb at idle. Is this as good as Seafoam or should I keep looking?

 

[ezeke]

Re: 1976 85 johnson has oil leaking out of carb

After a successful decarb, you can shine a light in the spark plug holes and see shiny metal on the piston tops. How did yours look?

NAPA stores usually have Seafoam and their aerosol Deep Creep. If you don't see it, ask them to get it for you.​

 

[smitty_bb]

Re: 1976 85 johnson has oil leaking out of carb

I found Sea foam, I ran a can of it in about 4 gallons of mixed gas, I also sprayed a whole can of "Engine De-carb" through the carbs. It seems to have helped, but its still not running right it feels like its holding back. It will not go up to WOT and is still fouling out plugs and leaking oil from the carbs. A friend told me to pull the carbs off, take the bottoms of the fuel bowls off and put the whole thing in a pot of water and boil it until all the "gunk" floated to the top of the water. does this sound crazy, or is there some truth behind it, he swears by it.

 

[ezeke]

Re: 1976 85 johnson has oil leaking out of carb

Follow the instructions in the manual and install new carburetor kits. The de-carb process is to get the built up carbon out of the cylinders, pistons, firing chambers and exhaust. Does not do much for carburetors, and is not meant to.

Be sure to set the floats properly and to install the connecting clips between the float arms and the float needles.