Excessive Smoke 1987 115 Yamaha

[87yamaha115]

My 1987 yahama 115 is smoking excessively when started or running slow. The on board oil switch was just replaced(used to run at all times). I figured the engine was getting too much oil and just running rich and that maybe the excess oil just needed to be burned off. I have run the boat for about 3 hours since the repair and it is still smoking really bad. Any help would be great.

[99yam40]

have you checked to see if the oil linkage is attached properly?
if it come loose it goes full on

[87yamaha115]

I want to say I’m 99% sure the linkage is good. I had a yahama mastertech diagnose the switch failure and they replaced it. Once they saw it fill back up with oil and stop when it was supposed to stop they gave it back to me. They never cranked it up and saw it smoke. Engine is running cool and not skipping a beat, just smoking like crazy.

[99yam40]

if you or they never looked , how can you be so sure?

[87yamaha115]

Can you explain to me what to look for when I check it out tomorrow. I know a little about outboards, but not much and I would like to cross that off if you think it may be the issue.

[panasonic]

Find your manual at this link. It will guide you through checking oil injection systems.

https://www.vansoutboardparts.com/se...a-shop-manuals

[99yam40]

look for the linkage that runs from the carbs to the oil pump to make sure it is still attached.
making sure it is adjusted properly is in the service manual.
I do not have that motor so I do not have a manual for it

[Jason2tpa]

Oil linkage 99yam is referring to and the oil "switch" you're referring to are two completely separate systems....mechanical and electrical. There's a cotter pin securing the linkage arm in place. If arm became unsecured it would separate from the lever and lever will flip up to full on unregulated release of oil

[rodbolt17]

nope.
on the kien pump if the link breaks it tends to shut off the oil.
the mikuni pump flips to wide open oiling.
as the tech that did this job I can tell you the linkage is or was when it left, ok.
my work order simply stated the transfer would not turn off.
I hooked the boat up, drug it around to the bay,used a heat gun to soften the 30+ year old vinyl drain,drained the tank. turned on the key and watched it fill. when it did not shut off I turned the key off, unplugged the engine oil tank, turned the key back on and jumped white to black.
the pump shut off as designed.
ordered the switch.
when I got the switch I installed it, drained and tested the system twice,3 bars, alarm and it shut off when full in less than 180 seconds.
moved the boat back to the yard and billed the hour that it took.
this customer did call back and say something about the smoke. this customer was advised to bring it back. this customer has chosen not to.
my guess would be a check valve in the pump has debris and is allowing gravity to bypass the pump and leak oil unmetered into the intake.
but what do I know.

[99yam40]

interesting, does that old 87 115 have the kien pump or the mikuni?

I had no idea some would shut off all oil when linkage was disconnected.
Very bad fail position

[rodbolt17]

all oil pumps for Yamaha were of the kien manufacture until 1990.
from 1990 they used mikuni pumps with inline check valves.
they did make a kit to convert the kien to mikuni. I don't know if it is still avalible but myself I would ditch the oiling system and premix if I had a motor that old.
last one I did the kit was almost 500 bucks. that was about 20 yrs ago.

[87yamaha115]

Redbolt, thanks for responding on here and you are absolutely right, you guys did fix the issue of the pump not turning off. It was also explained to me that the excessive smoke would stop within an hour of running it and it has only gotten worse. Being that it was the holiday week I wasn’t able to tow it an hour away back to yalls shop. I will most definitely be bringing it back to you guys though and I’m hoping y’all can figure it out.

[99yam40]

I was suprized to read he was someone that came to your shop.
small world some times

op you have already read what he would do

[dngharvey]

Have the same motor and had the same issue, in my case it was the tiny oil adjustment thread on thinghy that adjusts oil flow as throttle is advanced. Allowed oil amount to go full on and smoked like an s o b till figured out.