1999 Johnson 115 Barely Starts, Won't Stay Running

[Captain Jeff]

Hi Guys, I have a 1999 60 degree 115. At the beginning of the season I replaced the VRO/OMS with a brand new unit, rebuilt all 4 carbs including bowls, rebuilt the vapor separator and even put a new top on the primer solenoid. I also put a new primer bulb on the fuel line and cleaned the oil tank, refilled fresh oil and replaced the oil line and bulb to the engine. It ran great this summer.

I pulled it out of the water about a month ago and it sat since then because I haven't had time to winterize it. Yesterday I went to start it to winterize and it would barely stay running if I could even get it started. I was able to get it running for 30 seconds to a minute by mostly holding in the key for the primer solenoid. Finally I got it to run long enough by using the manual red primer lever to winterize it. It would only run with choke/primer. I was surprised since I went through the fuel system this spring. Fuel is always stabilized. The one possibly strange symptom I noted was that I heard the VRO/OMS click occasionally when I pumped the primer bulb... not sure if it was while I was pumping or when I let go of the bulb. Any ideas? Thank you

 

[Joe Reeves]

In using the fuel primer solenoid to have the engine running, you are bypassing the carburetors.

If for some reason, you ran the engine out of fuel when you were done with it, that allowed the carburetor float chambers to load up on raw oil... and if so, drain them!

 

[Captain Jeff]

Thanks Joe, that is a great point. I didn't run the engine out of fuel but I had a similar problem at the beginning of the season. When I went to rebuild the carbs, they seemed full of oil. Not sure if this is from the more volatile gasoline evaporating and leaving the oil behind or if oil somehow fills the bowls naturally. I wonder if the day/night cycle of warming and cooling somehow causes oil to pump from the reservoir into the carbs. During the season I would have good smoke at startup if I had not used it for a week but not much if I had used it the day before. I'll drain a couple bowls to see what is in there. Thanks again

 

[boobie]

Sounds like your oil tank is building up pressure when sitting and sending oil to the carbs. OMC did have probs with the caps on the tanks not venting. Leave your cap loose to prove a point or replace it.

 

[Captain Jeff]

Well guys, oil filled carbs is not the problem. I drained the bowls and they were full of clean fuel with a slight blue-green tinge from the oil. I do leave my oil tank cap loose because I don't trust it to vent. It is located in a compartment so water spray isn't an issue.

I am wondering if it is an ignition issue and the extra fuel from the primer makes it look like a fuel/carb issue. Maybe there is a weak spark that can't ignite the normal air/fuel ratio but it is able to ignite the extra fuel from the primer? I also had a weird feeling about the optical sensor because there was a little bit of mildew on the motor from sitting for a month. I was worried that maybe some mildew got on the optical sensor or timing wheel and affected the timing. I took it all apart and cleaned the sensor eyes with an alcohol wipe as well as the timing wheel. Cleaned and reinstalled the timing base with a layer of fresh grease. No difference.

 

[racerone]

Easy test for spark.---Does spark jump a gap of 3/8" or more on a tester, yes or no ?

 

[Captain Jeff]

Good idea, I'll test it with a spark gap tester. I think I am running the original coil packs. Thanks