Hi 1st post from new member, I`m from the Grimsby area and have had a DT125R for over a year. Bike is really good apart from after a ride i have a few spots of oil on the floor. The oil appears to be coming from behind the front cog. Is this just an oil seal failure and an easy fix or is this a more serious problem. Any help or advice would be appreciated.

Welcome besty, Aye there be a seal behind sprocket, don"t know the model, but you may be able to put screws into old seal and pull it out , and drift in new seal, get a manual for the model,

Be worth checking properly, when that seal goes usually the bearing behind it will be in poor shape too due to the crud from the chain getting in, that seal is there to keep stuff out probably as much or moreso than keeping stuff in. It may even be shaft movement thats causing the leak.

Be worth checking properly, when that seal goes usually the bearing behind it will be in poor shape too due to the crud from the chain getting in, that seal is there to keep stuff out probably as much or moreso than keeping stuff in. It may even be shaft movement thats causing the leak.

Gotta love mechanical inuendos! anyway, i was told that the Rd350's were often know for this seal going, I've also seen quite a few seen quite a few DTR engines with similar so is probably your cuplrit.

Thanks for the advice, think i`ll take her in for a check up