A forum for owners of Yamaha TTR250 trail and enduro bikes!

I recently fitted a rebuilt 250 engine to my own TTR to give it a thorough test before offering it for sale.

I was very pleased that it started and ran well but when I parked it up there was a bit of an oil drip under the engine 

The cam cover gasket and decompressor plug were both dry and closer inspection showed a shiny covering of fresh oil behind the tensioner. Some of it is just visible in the photo below:

The most likely culprit(s) are the banjo bolts and their copper washers. I had been lazy and not annealed the washers as I recommend in my engine build threads 

However, I thought it was too good an opportunity to miss and bought some Dowty washers to try. These are metal washers with a bonded rubber seal on their insides specially made for hydraulic applications such as this.

There is an advantage with them in that they aren't loose on the banjo bolt so don't drop into inaccessible place (like between the fins!) as the copper washers can do 

Externally they look the same except they are steel not copper.

About a 15 minute job as you have to remove the exhaust header and pop the shock canister up out the way.

Brian