MS290 Case plug/seal missing?

[DoItAll]

Hello,

I am doing the MS290 to 390 p/c swap. During disassembly, I found a stick wedged into the front of the case behind the muffler. It is the back side of the oil pump elbow connector. Thinking it somehow got jammed in there by some perfect chance, I pulled it out. Oil "burped" out for a bit all over the case. I assume there must be some sort of plug that goes in there but I do not see anything in the parts manual. Any idea?

 

[Dub11]

A set screw will do the trick. I just did one and found the closest size tap then corresponding screw.

 

[lwn9186]

9134 381 1230 is the part number for the grub screw that is in the Stihl bulletin if you want to go that route.

 

[DoItAll]

Perfect. Thank you both!

 

[lwn9186]

Make sure and don't set the screw in too deep or it won't oil.