PT Carburetor regurgitating!

[ldabe]

HELP! PT-422 (Robins/Subaru eng.) cranked over and began to run for about 3-5 seconds, stopped running, and as soon as it stopped fluid shot out, like it was REGURGITATING! Out of what I thought was a breather tube (I don't have a schematic for the carb so don't know exactly what that port/tube is). At first I thought the fluid was gas, but turns out to be gas mixed with oil (see pic). I cleaned the fluid up and it did the same thing 2 more times!
Can anyone tell me why fluid is coming out of the port/tube, where it is coming from, and the possible fixed that I may be able to attempt. I appreciate all you PT guys on here, and the help you have always provided me.
(Also, I have been away from this forum for a number of years because of moving and not having much use for the PT, and some personal events that occurred in my life.)

 

[MossRoad]

Check the level of the oil in the crank case with the dipstick. gas may have leaked into the crank case through the carb. thats where i'd check first. if it did, you'll have to drain the oil, change the filter, and refill with oil.

 

[ldabe]

MossRoad,
The oil level looks good. Or did you mean check to see if there is gas in the oil on the dipstick?
Do you know what that port/tube is called, and what is it for?

 

[ldabe]

Btw, last year I was having problems with it not starting. Turns out the Fuel Solenoid on the side of the carburetor was not working. So I broke the plunger off, and just made sure to turn the fuel shut off valve in the off position to clear gas from the carb and shut the engine down.
Could that have something to do with this new problem of "regurgitation"?
But I thought maybe I should get a new one, contacted Terry at PT, he said they cost over $150! So I didn't get one.

 

[MossRoad]

MossRoad,
The oil level looks good. Or did you mean check to see if there is gas in the oil on the dipstick?
Yes, check if there's gas in the oil on the dipstick.

Do you know what that port/tube is called, and what is it for?
No I don't. I suspect it's a breather from the crank case, but don't take my word for it. Just a suspicion.

Let us know what you find.

 

[agjones]

Yes, breather.

 

[ldabe]

Yes, breather.

AGJONES, Do you know why fluid would come out of the "breather" port/tube?

 

[marrt]

Btw, last year I was having problems with it not starting. Turns out the Fuel Solenoid on the side of the carburetor was not working. So I broke the plunger off, and just made sure to turn the fuel shut off valve in the off position to clear gas from the carb and shut the engine down.
Could that have something to do with this new problem of "regurgitation"?
But I thought maybe I should get a new one, contacted Terry at PT, he said they cost over $150! So I didn't get one.

Yes, this could have something to do with your problem.

This Subaru engine is notorious for leaking fuel into the cylinder heads and contaminating the oil (killed my last engine)...I assume, due to the needle value failing to seat. However...this could also be related to the failed fuel solenoid (which, I didn't know the engine had since I haven't been into the carb of my dead engine).

The combination of oil in the gas coming out the breather, but no gas in the oil in the engine makes no sense to me. For example, the oil level would need to be high to get past the oil rings. This usually occurs when the engine case fills up with gas...due to a problem with the needle valve, fuel solenoid, or fuel pump (leaking fuel into the engine case).

Either way, I don't see how you'd have a thin oil/fuel mixture at the breather AND not see or smell any gas on the dipstick.

To move forward, I would shut the fuel off and remove the fuel line from the engine to ensure no more leakage and confirm the shut off valve is working. Then, change the oil and filter. Reattach fuel line and open the shut off valve while cranking the engine. Once the engine starts, let it run a few seconds then shut off the fuel and let the engine die of fuel starvation. Change the oil and filter again...even a very small amount of gas in the oil will change the oil's viscosity.

You've now confirmed the engine is ok, but you don't know the root cause of your problem (assuming to didn't discover something like a failed shutoff valve). I would replace the carb solenoid and give strong consideration to adding another electric fuel shutoff on the fuel line (I just added one to my tractor). If you don't want to go further with the diagnosis, then you have to ensure no fuel can get to the carb when the engine is off. A manual shut off valve isn't good enough because you'll eventually forget to shut it off and potentially ruin the engine.

My two cents.

 

[cqaigy2]

Nice write up marrt!

I could surmise the reason my robin's engine failed, was because i only changed the engine oil and filter one time, after filling crankcase with gasoline, instead of what marrt says about changing it a second time.

 

[ldabe]

Thanks for your input Marrt, and to all others.

I need to get this giant paper weight out of my back yard and the elements (Sun, Rain, etc.) into my garage to work on it. BUT!
I have to push it By hand (hopefully with a couple other guys).
Terry (from PT) said there is a hydraulic relief valve/stem on mine under the hydro motor and to turn it clockwise. This is the Tow valve for my 422.
This is the dumbest place for it! the valve/stem has a hole in it to put something through it and to turn it. I tried using an allen wrench and it broke the allen wrench when I tried to turn it clockwise (and I am assuming this is clockwise if you were looking at it from the bottom).

Has ANYONE been able to get this valve/stem to turn?

Also talked to representatives from Subaru/Robin (who sent me schematics of the engine). They have never heard of this problem of "regurgitating" either, and basically said to start with the basics of taking off the carb, cleaning it, getting a new fuel solenoid, changing the oil, filter, and spark plugs.

But, I really need to get it into the garage to do anything. And in order to do that I need to get that Tow valve to turn.

If ANYONE has had experience in turning theirs, please let me know how you did it and what direction you were turning.

I can barely get my hand under there to find the valve, then the hole, and to get something in the hole to try to turn. FRUSTRATING!