Here is what I did to clear out my oil supply line to the rocker arms on my 235. I pulled the rocker arm assembly to access the supply hole in the cylinder head. Then I used a piece of copper wire (14 gauge I believe) to snake the hole. Then I took a large syringe to suck out the supply tube. This didn't work at first. So I used some penetrating oil and sprayed it down the hole. Then the copper wire, syringe. Oil, wire, syringe. It took me a while(about an hour) but I was able to clear the line.
