Subaru EX17 belching smoke, black runny fluid

[henni]

Subaru Robin EX17 engine on a washer, took carburetor completely apart, cleaned primary jet (pencil eraser size) and the longer tube with tiny holes, some of which were plugged. Re-inserted the longer jet tube and then discovered the smaller primary jet would get stuck in the threads and had to use a left handed drill bit to reverse it back out before being able to re-thread the jet.

Now it starts and runs but belches occasionally a plume of smoke, black fluid spits out from muffler.

It it because of the primary jet now having a larger opening at the base ? New jets cost around 10/each plus postage but entire new carb is 90 free shipping. Not sure the primary jet is a standard small engine part that could be sourced from any small lawnmower parts depot or similar ?

 

[old1]

I believe you messed up the main jet, and yes, you need the right one, not some universal thing, but it doesn't need to be genuine Subaru.

 

[Dallas69]

Sounds like you have a lot of gas in the oil.
You better check the oil and change it.
Do you have a gas shut off?
One time on my Mom's riding mower gas drained into the oil and it spit out black liquid.
Put a shut off on it and fixed it.
Drained the oil and it was like water.
At least the engine got cleaned inside.

 

[henni]

Oil was changed at same time with carb cleaning. No fuel in oil, proper level confirmed. At time of the oil change, it also appeared to be completely clean oil, barely any trace of color variance from new oil.

 

[gman2304]

Is this the same engine you replaced the carb on recently in another thread?

 

[henni]

All new OEM Carburetor, not just parts, not rebuilt, installed today. All fluids changed. Both CAT 30W ND and Engine oil were like brand new as they were drained, no evidence of color or water in either fluid.

Started immediately, even without choke, revved up and upon pressure release, Idled down just like new.

After about 2 minures, black smoke again, plumes and clouds from muffler and it eventually stopped.

Waited few minures, started up again, ran strong, black clouds from muffler and engine stopped.

 

[henni]

Small correction, not black but white smoke, the fluid from muffler is black but that could be due to carbon being steamed from muffler walls as the smoke puffs out.

Now am thinking it has nothing to do with carburetor, could it be a leak in the pump causing water to inject into engine

 

[henni]

Found solution

https://www.ridgidforum.com/forum/power-...her-blows-smoke

 

[Cujet]

Originally Posted By: henni
Found solution

https://www.ridgidforum.com/forum/power-...her-blows-smoke


I read that link and did not see a solution. But rather a few suggestions.

Did you actually find a solution?

 

[meep]

i'm thinking clogged breather--- crank case is building pressure and then oil is either getting pushed into the intake or burping to combustion via valves or rings?

 

[bubbatime]

Drain the oil. Your old carb dumped a gallon of fuel into your oil. You probably wont see the gas on the dipstick, and it won't look overfilled.