Hi Guys,
Well, as you know by now, the bike shifts fine, but still have a leak, and I suspect it is coming from that plug!
I have a replacement plug, but I cannot figure out what is behind it! Has anyone replaced this before? Looks simple, but I don't want to damage anything when I drill into it.
Thanks!!!
Roland

Clutch shaft or shift shaft?

if it is the big plug at the end of the shift drum (#7) I would not drill into it and instead pry it out with a small chisel after banging it in radiall from the OD.

Hello Roland, Andy here from the UK.  In trying to help you with your thread I'm assuming that msavitt has correctly identified the 'plug' you are trying to replace?  If so then I have replaced that plug myself although I did it when the halves of the crankcase were split and so it was simply a matter of knocking it outwards.  However from my memory of the shift drum design (it was approx 18months ago) you can remove/replace the plug externally.  As msavitt (sorry I don't know your first name) says you don't want to be drilling anything as swarf and engines/bearings don't mix.  I remember the shift drum is different from the other shaft materials because it is a machined iron casting.  The LH end of the shift drum casting behind the plug is actually hollow for approx 10 - 15mm and then it simply becomes a flat unmachined roughish face.  I reckon you could 'puncture' the centre of the plug with maybe a pointed dot punch.  Next screw a hard self tapping screw in to the puncture hole to open it up a little.  Finally take a longer self tapping screw maybe 30-35mm long and screw this into the hole and when it contacts the shift drums flat face it should jack the plug out as you continue screwing.  In case my memory has failed me (too much Jim and Jack..!! ) and it doesn't prove successful, well no harm has been done as a hole in the plug is a good starting point for trying prising, pulling or other techniques etc.  A word of caution though is to stay away from the outer diameter of the plug as there is a shoulder the plug sits against to stop you pushing the replacement plug in too far.  Behind this shoulder is a needle bearing the shift drum locates into hence the reason for not wanting to generate any swarf during the process. Self tappers could create a single lump but simply sweep the recess with a small magnet to clear it out.  Good luck and hope this helps.  Andy.

Unusual for those plugs to leak for no reason. If you replace them, don't tap the selector drum big one in too far, just flush, or same for both really.

Thank you so much for that much needed information. I will replace that plug this weekend!!! So glad I have some room to work with behind it!
Roland

Good approach Andy. I would add that if one decides to drill into the center of said plug, put some grease on the drill bit, and it should catch almost all of the drillings. Have a magnet handy also.

before ya do all that. ya sure its not the sprocket seal leaking or sprocket nut loose so oil's running down there n dripping off.

Hi Guys!
Thanks for all the tips, but I think I may have found the source. It is not the countershaft sprocket seal because I can view behind it and it is dry. Oddly, the bike does not leak oil NOW unless it has been ridden. The source seems to be coming from the carburetor, which has a slight leak (running pre-mix now as the prev. owner Fkd the pump up when trying to rebuild it. He Fkd up a lot of stuff which makes me suspicious on everything he did. Thank goodness I caught it before riding it and now waiting on the rebuild kit!) that runs down and behind the countershaft sprocket cover, over the black plug in question and onto the floor. It is just a wee bit and it takes a few rides for it to drip now, but this will be easily solved. After changing the Shift shaft seal it all but went away. I have no pan under the bike to catch oil and there is nothing on he floor.
I am very happy!

Ha, yeah, those leaks often start from elsewhere & run. Good ya found it.