On the bottom  of my RT3 engine are two drain bolts, one on the left of the engine case and one across from it on the right. The right hand one looks like a slightly smaller head and I can find it on the parts diagram but the larger on e on the left isn'i indicated on the parts diagram. I want to replace both with the washers but I only have part numbers for the one on the right side. Need help for the one on the left.

The left bolt houses the  detent spring and follower for the selector drum .
You can see them on the shifter page of the parts book .
Drain bolt gasket and detent spring bolt gasket are both identical .

Just looked up what you said and there they are on the diagram. Thanks. I do have a lot more to learn about this bike though. Now I have to find out what this bolt and spring for the shifter exactly does. Thanks again.

Holds it in every gear plus neutral. You'll soon know if its fallen out in the oil drain tray if you drained the oil through that one, as the gearchanging will be all up the creek. & you sure wouldn't be the first one to do that!!.Easy trap.

Great, that answers that. Should that be checked for wear occasionally or if the bike shifts okay just leave it alone? Thanks in advance.

No need to check for wear...  if bike is new to you, make sure detent plunger and spring is there and plunger is free.  Then leave it alone.  It's not meant to be a drain and does not need to be removed during a trans oil change.

The bike is relatively new to me so I'll pull the bolt and check to make sure it is as you say it should be. I'll do it this afternoon. One more thing off my list for this bike. Thanks Mark.