96 Johnson 130 HP Oil and Gas Leak

[MN_Sailor]

Sorry for the long story, but I figure giving all the info might help diagnose my problem.

I just recently had this oil drip down from just above the mounting bracket above the lower unit. I could be wrong, but I'm assuming the oil is dripping down the exhaust shaft? To me, it looks unburnt and not mixed with fuel from the VRO pump. According to the manual, the only way that's possible is from an external leak. Of course, all the hoses look good, and I don't see any oil resting in the motor housing.

Secondly, I'm getting some decent sized gas puddles after idling or cruzing around for a bit. They don't seem as bad after driving, compared to just idling. I've read these motors can have some unburnt fuel that comes from the exhaust. However, this just started happening.

So, the chain of events that lead to my current problems:
Motor always idled rough, and would bog down occasionally. Replaced fuel filter which solved the problem initially. Boat ran better than it ever did, for 2 days.........

Carbs started leaking so tried the Johnson engine tune up spray. This is when I noticed the oil drip and gas leak after using the spray.

The tune up spray didn't help the idle or carb leaks. Ended up rebuilding all 4 carbs. One of which had a tear in the gasket mounted to intake. Also replaced all 4 spark plugs. They were wet, and a little brown, but sounds normal from the oil/fuel mixture.

Used an inline spark tester, and all coils are firing. Next weekend I'll check compression in the cylinders.
I've had the boat out 3 times since the repairs, but no change in the amount of oil and gas leaking down shaft and in water.

Thanks for any help. I'm kind of baffled.

 

[Bosunsmate]

Is the motor running ok apart from the not so great idling?
The tune up formula may of loosened some old oil which over time has covered the inside of these motors in the housing and thats whats now leaking down.
Does the primer bulb stay firm when the carbs are primed and engine is off?

 

[MN_Sailor]

Is the motor running ok apart from the not so great idling?
The tune up formula may of loosened some old oil which over time has covered the inside of these motors in the housing and thats whats now leaking down.
Does the primer bulb stay firm when the carbs are primed and engine is off?

I'll double check the bulb, but believe it does. Occasionally, I couldn't get the boat faster than 8 mph when full throttle. It seems very bogged down. It would pick up for a second, then back down. It seemed after it warmed up during the day, it ran better and top speed back up to low 40's. I didn't have that problem at all last weekend though. That just started happening last year, and is very intermittent.

That was another reason I rebuilt the carbs and changed the fuel filter.

 

[MN_Sailor]

Here's the rundown so far.

Boat started and idled perfect last night. No oil or gas leaking anywhere. Compression was 120 on all cylinders. Took off plug wires one at a time while boat idling, and each one idling got worse. Motor stayed running, then back to normal when plug wire pushed back in. One plugs gap was slightly off, but only by .05

This morning, motor took a few tries to start. Wouldn't stay running on normal idle, so had to advance throttle forward to fast idle. Spark tester lit up on all coils/wires. Decent amount of unburnt gas in the water. After starting and stopping the motor numerous times, checking various things, it seemed to finally idle normally. Ohm meter on plug wires all checked out.

Took the boat out, and she ran pretty well. Bogged down a bit at full throttle, but picked back up and ran good. Pulling up to the lift, the motor stalled out at idle. Restarted to pull forward on the lift more and died again. Happened a few more times until the boat was fully on the lift.

More gas in the water, and now some yellow oil leaking again. Doesn't seem like as much oil as before.

This seems to be the pattern lately. Sometimes boat idles and runs great, other times the idle is rough, stalls, and boat bogs down, and can't get it to run faster than 8mph. The gas in the water from the exhaust is new. Do I need to pull the carbs off again? I didn't take out the little mixture screws to look at the needle valve. Really don't know what or where to go next.

Thanks

 

[racerone]

Stop trying to run this motor.-----Remember a plugged carburetor jet can lead to serious engine damage.--So make sure they are clean.----Also check the flywheel key.---Is there a water seperating filter in your boat ?--Test run with another tank and hose.----Hook up a timing light and see how spark behaves.-----Have an assistant operate the manual fuel pump.

 

[MN_Sailor]

I cleaned and rebuilt the carbs a few weeks ago, and replaced the fuel filter as well. Also used the OMC engine tune up spray.

Just started the motor after lunch, and she fired right up and idled perfectly. Will have to check with a timing light next. Read a few threads that a bad thermostat could actually be the bad idling and bogging down issues. Will have to check how hot the cylinders get.

Thanks for all the recommendations and help. Would love for this thing to just work right all of the time.

 

[Bosunsmate]

yes check it opens and closes. Eventually you will get it running right and itl all be worth it

 

[MN_Sailor]

Turns out one of the thermostats was bad. Boat seems to idle fine now. Doesn't bog down either. Ran fine all day. Hopefully tomorrow is the same.

Second, I think it's gear oil that is possibly leaking from the shift shaft. Looks like there are a couple o rings and gasket for the shaft housing. Is this a common thing to go bad? I had the lower unit seals and water pump done by a marine mechanic a few years ago. The oil that is leaking is yellow, and doesn't seem to be mixed with water.

Gonna take the boat out of the water and drain the lower unit and pressure test it. Any other thoughts? Appreciate any suggestions.

 

[Bosunsmate]

yes do as you are intending too, look at the level closely, if thats ok and the oil is only slightly off colour then id assume its ok in there

 

[MN_Sailor]

So how exactly and when does the SLOW run kick in? Was getting the boat off the lake, and it wouldn't run over 2200 rpms. It would also die on idle again. Eventually got it on the trailer. Did I not let it idle enough and get to temp? Or is it a safety feature when I start the boat in fast idle? I was pretty upset it ran like garbage to the boat launch.

 

[Bosunsmate]

they always need warming up, should take a minute thereabouts unless very cold water.
Slow kicks in when overheating

 

[MN_Sailor]

Drained lower unit, and quite a bit of water came out first, followed by milkly yellowish oil.

Air compression test confirmed leak originating from shift shaft seal. I can hear and see the air/bubbles.

Assuming the oil was being pushed to the top by the water, and out the shaft seal.

 

[MN_Sailor]

they always need warming up, should take a minute thereabouts unless very cold water.
Slow kicks in when overheating

Thanks for the feedback. Thought I finally had the idle issue under control after it ran so we'll yesterday. The motor definitely wasn't overheating. Any suggestions where to go from here? I've changed plugs, inline fuel filter, and checked coils and wires for spark. Also redid the carbs, but didn't mess with the idle screws. Probably should take those out and inspect/clean them. Will check for vacuum leaks as well.

Thanks again

 

[Bosunsmate]

Check if you have spark when it runs bad. And try a drop test on each cylinder. Find out if its spark or fuel. Turn the motor off and look at all sparks, see if they are dry or wet.
You could try unhooking the overheat sensor in case that is putting it in slow mode inadvertently
No worries, glad to help. Its quiet here in New Zealand in winter

 

[MN_Sailor]

Took the lower unit off, and both shift shaft o rings were bad. One torn, and the other warped.
​​​​Boat is out of the water, but no oil leak on the muffs after replacing those.

Not that I'm complaining, but boat has fired up, and idled great so far. Did a spark gap, drop, and coil ohm test, and everything has checked out. I disconnected both temp sensors, and one of the electrical connections inside its boot was a little corroded. Cleaned it up, and applied some dielectric grease. Would be great if that was the intermittent issue.

Won't get the boat back out on the lake for a few weeks unfortunately. We'll see if it starts and idles the same tomorrow.

 

[MN_Sailor]

Had the boat out a few times this weekend. Oil leak gone, and motor never went into SLOW. Seems like it just has to fast idle for a bit to warm up, then it idles fine. Probably could try syncing the carbs, and/or adjusting the idle speed.

Kind of weird that after a week of sitting, it fires right up and idles great. It seems like it stays in fast idle possibly? The rpms are roughly 1000. Everytime, the next day of starting, it doesn't seem to fast idle, and dies. I have to increase the idle from the shifter when starting. After it warms up, seems to idle fine at 700-800 rpm's. Either way, seems like it's running much better. Thermostats and shift shaft o rings were the culprits. I may try disconnecting the temp sensors and see if that helps with anything.

Anyways, those that commented, thanks for the help.

 

[oldboat1]

You seem to have an aversion to needle valves. You cannot make proper adjustments on muffs, so with the boat in the water and warmed up in neutral -- Make slight adjustments clockwise (leaner) until the engine sneezes, then turn counterclockwise 1/4 turn -- should be the correct setting. Check by making sure it goes into gear smoothly without stalling or stumbling. If the motor is idling to high after the needles are set, adjust the throttle idle setting.