She's spitting oil!

[toddingalls]

My 1990 Yamaha 115 2 stroke is spitting oil from the prop, quite a bit... see attached photo.
Smells like gas/oil mix which makes me think I am just running too rich, but I have oil injection.
Tried running premix oil/gas for about 10 minutes with same result.
Am I just burning off excess oil? Or is there another problem?
Runs rough, backfires. Plugs are also oily. Changed plugs a coule times already.
Any ideas?
Any help would be much appreciated.

[99yam40]

Check the fuel pump for pin holes or tear to start out with

[toddingalls]

Update: Ran new plugs again, all 4 plugs came out oily. Carb floats seem okay. But I noticed carb floats don't rest parallel with the carb housing. They are kind of angled upwards. Do I need to bend these down so that they are parrallel at resting position? Seems strange for all 4 to be angled up like that.

Also, when I ran the premix oil/gas I just took the control arm off of the oil pump to disable it... would that method actually disable the oil pump for proper testing?

I will check the fuel pump for holes and tears also.

[99yam40]

I believe that if the oil arm breaks or is taken off it will go wide open and put max oil into the system

Not sure what you mean on the float, is the carb turned upside down and the float is not level when needle is closed?

[toddingalls]

Do you know how to disable the oil pump so I can test with premix?
I will test the carb floats again upside down.
On another note, I notice that the primer bulb doesnt get fully firm. Would that have something to do with the problem?

[99yam40]

If the bulb does not get firm then the fuel is still going some where when you keep pumping it

[toddingalls]

Update: primer bulb gets firm when pointing arrow up now.
Adjusted the oil injection to a lower setting, seemed to run a little better, but still running VERY rich. Oily plugs and still a lot of unburned oil and gas coming from prop exaust.
Checked fuel pump diaphram.. no visible holes/tears.
Any ideas anyone how to fix the unburnt oil gas problem?

[toddingalls]

Still having problem with HEAVY unburnt oil and gas coming from prop exaust... any help from members?
This what I done so far:
-Cleaned carbs
-Changed plugs x 2
-Disconnected and capped oil injection line to test with premix
-Checked fuel pump diaphram for rips and holes
-Replaced primer bulb
-Checked floats and float needles

[200090tlry]

holly shabogon

You have a problem captain wonder if enricher is bad have you tired turning that closed. I hope that is not gear oil, have you checked it lately. Do you know how to adjust carbs correctly. I suggest not touching the oil injection if you know this outboard ran good for awhile.

[robert graham]

Maybe you need to take your motor to the lake and run it wide open for a few minutes to clear out the gas/oil build-up in motor. It may just be juiced-up/flooded from running it in your driveway! good Luck!

[toddingalls]

I just got the boat about 3 weeks ago. It was an existing problem I am trying to get fixed.
I will try the enrichment valve and verify gear oil, and report back. Thanks for the suggestions.

[toddingalls]

Update: I had a few setbacks with the electrical system during this process... turned out to be a bad battery wire. But, anyway I can now get it to start again. Still running rough. Can anyone tell me how to adjust the carbs correctly on this motor? I have cleaned the carbs, but not adjusted them yet.

[toddingalls]

Okay, got my oily exhaust problem fixed... re-cleaned carb jets and adjusted fuel/air mix... and that did it!
Now I have another problem... runs and idles okay in drive-way, but won't idle good at launch ramp. Maybe being on the slope of the ramp is effecting my gas lines somehow?
Primer bulb doesn't really stay firm in either location.
Any ideas?

[SBSYNCRO]

Okay, got my oily exhaust problem fixed... re-cleaned carb jets and adjusted fuel/air mix... and that did it!
Now I have another problem... runs and idles okay in drive-way, but won't idle good at launch ramp. Maybe being on the slope of the ramp is effecting my gas lines somehow?
Primer bulb doesn't really stay firm in either location.
Any ideas?

Is the difference between having the cover on or the cover off? I've had some weird problems like that in the past (ran great one minute, then the next day no-go) turned out to be some pinched wires that were resting against the cylinder heads and being pinched by the cowling. Make sure the difference isn't whether the cowl is installed or not. Took me a while to figure that one out!

[axolotl98]

Concerning your first post, its just a matter of your oil pump, overdosing the oil.
Try to adjust the oil pump operation according to specs in the Yamaha manual.
Carb adjustment is only done in the floats (16 mm height from the flange) and the idle screws (5/8 of a turn, ranging from 3/8 up to 7/8).
Needs some experience to adjust the carbs. Ideally put the boat in the water, and spend a couple of hours adjusting the idle screws.
As a general rule, you want to adjust the motor to operate very smoothly at tick over, without any hick-ups.
Remember that the idle screws adjust fuel mixture quantity, they do not just rich or lean the mixture.