Well, trying to bring my old Attex ST300 out of mothballs (been parked for about 10 yrs since original JLO 297 became hit-and-miss & finally wouldn't start at all)... Fun machine when the old 2-stroke would run, just not reliable enough now for my needs at 67 years of age, ha! So, in my infinite wisdom, I'm repowering with a new 4-stroke Predator Max 459cc motor from Harbor Freight. Took some doing, but finally got installed and engine runs great! However, after removing xmsn, flushing old fluid out (yuck - pretty filthy!) & refilling with 1 pint of fresh 80/90 gear oil, then reinstalling, I immediately noticed a MAJOR oil leak between the clutch unit and brake disc (apparently where the concentric shafts meet?). Never had an oil leak there before, but now I'm wondering if that was just because the xmsn was never properly filled before?? Anyway, I really DON'T want to tear down the xmsn if I can avoid it, so my plan right now is to just try and limp it along for awhile longer (prob only run it a few times a year with the grandkids) by changing to higher viscosity SAE 140 gear oil and adding a leather strap slinger around the shaft to control oil slinging (like the old timers, ha! - now I ARE one!!). Hoping to change the gear oil with xmsn in place, if possible, (don't wanna remove again if I can avoid it!) and wondering if the little Allen screw I noticed towards the bottom of the casing is, in fact, a drain plug of sorts? It's not exactly opposite the big Allen plug fill port (and seems pretty small for a drain, too), but not sure what else it could be?? Can anyone confirm before I remove it & see?? THANKS!