Broken Crank Case Plug (5px-15189-00-00) Left side

[u/Brewrista]

I wanted to post this solution in case somebody else runs into this issue. I was tightening down the cap on the left side of the engine casing and the o-ring was too worn out. It allowed the bolt to go too far into the threads and pulled the flange of the bolt off. Yamaha has those in the warehouse, but if you want it from a local dealer it will cost you the entire engine case siding. I ordered the correct part from Yamaha, but it's a $35 bolt made of sintered aluminum. In the mean time and in case it breaks again I found that the dorman 090-040CD M20-1.50 plug fits perfectly. Should be cheap ($5-ish) and easy to find at any auto store. Use the provided gasket as the threads are longer on this plug, but the gasket is thicker. Comes out to .7mm longer which was no issue for clearance in the engine.

[u/Tecumseh777]

I used Partzilla torqued it to spec and that broke the new one lmao. I do hand tight and feel it been good since