Oil leaking from carbuerators

[toddingalls]

1990 Yamaha 115 hp 2 stroke
New problem... I have a slow bleed of fresh 2-stroke oil out of carbs.
Keeps slowly flowing as long as there is oil in the engine mounted oil tank.
It looks like I don't have check valves installed on the oil lines. Seems like they are just little plastic couplings to me. Not sure, but when I removed a coupling from an oil line I could see right down the middle of it.... Could this be my problem?
Or Replace oil pump?
Or rebuild pump somehow?
(I have oil injection obviously)
Oil Pump is a KEIHIN... not sure if this is the recalled pump that I am reading about or not.

[jb123]

pull off recirc line from breather, see it flows from it

[toddingalls]

After some research I found out that the old Keihin oil pump does not have in-line check valves. It has internal check valves.
jb, where is recirc line and breather located?... on the oil pump?

[jb123]

the recirc is the vent line off the main oil tank
the breather box is cover over carbs, recirc should plug into it, allowing overflow oil to be burned
i know his is the case on the larger motors not positive on the smaller
you say the oil is coming out of the carbs

[toddingalls]

JB, it doesn't look like I have a recirculation system with my 115hp.
Does anyone know how to test the oiler? The oil keeps slowly bleeding out of the carbs. The oil tank on the motor is mounted higher than the carbs so gravity is just pushing it through, I think.
Seems like the internal check-valves of the pump are not working, not sure though... looking for feedback (obviously)

[wyobulldog]

I am having the same problem! I have a 1984 or 85 Yamaha 115hp V4. If it has oil in the main oil tank on the engine it drains out of the bottom carb when the engine is tilted up for transport or storage. I replaced the control module and oil tank sensor thinking that it was pumping the oil out somehow but it still drains out. I think it is gravity also and as you say maybe a check valve in the top of the pump where the main feed line goes in from tank. Looking at my Seloc manual I don't see a check valve but when I look at the oil pump online it says that it is a conversion, maybe a new design that fixes the issue? If you have figured out the problem please let me know! I am sick of cleaning up the mess!

[rodbolt17]

two choices.
replace the defective kein pump with the mikuni kit or remove the plastic couplers and install 4 inline check valves.

[wyobulldog]

Thanks for the reply Rodbolt! Can I just pull the lines from the top of the pump and put the check valves there, or just put one on the main feed line from the tank to the pump? Where could I order said check valves? Is it a hard job to replace the pump? Sorry for all the questions but I searched the web last night for hours before finding this post and it was the closest to my problem. Thanks again!

[rodbolt17]

you will need to purchase the later style inline checkvalves and install 4 of them in place of the original couplers.
or buy the mikuni replacement kit.

[hazmatman]

Excessive smoke just after take off

I think I'm having the same issues. After I start the boat and let it warm up we take off and get a little ways from the dock and the motor really starts to smoke. you can be 1/4 to 1/2 mile ahead and look back and the smoke is still coming out of the water. Go a mile or 2 and everything clears out and just the normal smoke of a 2 stroke. The rest of the day it runs great. So I'm guess the oil is loaded up in the carb from traveling and sitting in the raised position. I use a transom saver but it's not tilted very high just enough so i don't worry about it hitting anything. Any info would be greatly appreciated. By the way I did order the check valves to install in the lines going to the carbs. Waiting for spring to install. Just wondering if this will take care of problem.