New guy here. Recently bought 1st trials bike. A sherco 290 2007. Really happy with it and went out 1st time last weekend and loved it! I replaced the oil before I went as wasn't sure on the last time this was done. I've decided to change out the coolant last night and when i removed the drain bolt out the side if the water pump, noticed it was a cut down bolt obviously not made for the job. The sealing washer was not there either! I've found the correct sealing washer online but cannot find the dimensions for the bolt I need to replace it properly? Anybody shed any light on this please? Also last week the clutch was sticking quite a bit, even when hot. I had to give it a bit of revs with the clutch lever held in to free it. Would swapping to a different oil help this or is my clutch shot? I put 450ml of silkolene light gear oil 75w in. Thanks for your help in advance ?

Malcolm Rathmell Spares, Dirtbike Express plus many other suppliers are out there to help you. You might find that the non standard drain bolt is actually better than the original, with the correct sealing washer it should perform ok. Before anyone berates me, I haven’t seen the offending non standard bolt but I have a good crystal ball.???‍♂️??

the original bolt is kinda special little short 5mm sucker. if it has been hit and damaged the threads, a 6 may have been rigged up. the bolts are inexpensive.

Cheers for replies. I think the 1 they rigged up might be too short by the time I've got a washer on the back ?. It sealed before but I just want it right so I'm not worried about it. 

If you are not sure what length bolt to put in there, just purchase one of the correct diameter and thread pitch but a little longer and install your chosen sealing washer and then remove your water pump cover and trim to correct length allowing for slight washer crush room so it does not contact your impeller...and be careful you do not over tighten it.