KT17 Blowing oil out of dip stick tube

[muz123 1,191]

The 280 hour KT17 in my 417 is all of a sudden blowing oil out of the dip stick tube while it is running. What could be the issue? A breather?

 

Thanks

[8ntruck 7,016]

Breather sounds like a good place to start. 

 

What kind of fuel pump do you have?  Might be possible that the fuel pump is leaking gas into the crank case, raising the oil level, causing extra splashing.  Check the consistency of the oil and the oil level.  Gas in the oil is bad - to the point it can take out the engine.

[Pullstart 62,912]

Is it running alright otherwise?  Too much crankcase pressure... possibly a piston/ring issue?

[953 nut 55,321]

9 hours ago, muz123 said:

all of a sudden

If this were a gradual change I would suspect the breather. As stated above, check the oil level and run a compression check or a cylinder leak-down test.

[pacer 3,173]

While fuel could have entered the crankcase, I have reservations about that. With your saying "all of a sudden" to me would indicate a more serious problem in that a piston has --- had a problem? allowing pressure to enter the case and cause the "old faithful"

[muz123 1,191]

On 4/9/2021 at 6:39 AM, 953 nut said:

If this were a gradual change I would suspect the breather. As stated above, check the oil level and run a compression check or a cylinder leak-down test.

Removed the breather and it was covered in oil. 

[muz123 1,191]

On 4/8/2021 at 9:48 PM, pullstart said:

Is it running alright otherwise?  Too much crankcase pressure... possibly a piston/ring issue?

Yes it runs good, just sputters at different engine speeds and puffs blue smoke now, and has lots of blowby. 

Edited April 10, 2021 by muz123

[lynnmor 7,308]

3 hours ago, muz123 said:

puffs blue smoke now, and has lots of blowby. 

 

Time for an autopsy.

[oliver2-44 9,761]

With it running pull one plug wire, the reconnect and pull the other. See if that will tell you anything about one of the cylinders