OK, I need someone with a dirty tool less cap problem to try this.
Get a Stihl 0000-359-1210 gasket and install it in the groove above the oring. You will want to lube it up well and it will make the cap fit tighter, but I think it may keep the dirt out. I tried it on a MS290 and it fit. Let me know.
Get a Stihl 0000-359-1210 gasket and install it in the groove above the oring. You will want to lube it up well and it will make the cap fit tighter, but I think it may keep the dirt out. I tried it on a MS290 and it fit. Let me know.