Oil leak. Advice wanted

[budget biker]

merry xmas all
just noticed a pool of oil under my sons bike today,rm125.it appears to be coming from behind the front sprocket.i took off the chain but dont have circlip pliers to remove the sprocket with.im guessing the seal around the spline has gone.fairly sure it is not over spray from lubing the chain.it is about a teaspoon or so.
questions. 1 would the bike be okay to ride like this ? or too risky and may damage transmission\engine
2 if it is the seal can it be replaced externally?
also ocasionally the rear shock has no movement but then returns to normal. worn shaft sticking? stuffed shock?
.we did have a couple of rides lined up but may have to wait for shops to open to get repairs.
thanks in advance for any advice

[barty5]

it will last a little while the seal and normally the oring can be done externally may pay to replace the steel sleeve as well that run inside the seal as they wear out as well. the shock id remove and check all the linkages first odds are one is rusted up causing it to lock up be careful as old bike i had once years ago split open the bearing housing one one of the linkages due to this whole arse end of bike sagged out on landing off large jump.

[unstuck]

Should be fine for a couple of rides, and you should be able to do the seal externaly. Enjoy you ride.