I plan on doing an valve adjustment on my 400ex soon. In my Honda manual it suggests I replace the o rings on the valve adjustment covers, and both the little covers on the side of the engine case. I didn't do this the last time I adjusted the valves and feel I may need to do it this time. Are you replacing these o rings when you adjust your valves? The only place I can find these o rings (except the dealer) is www.bikebandit.com and they range from $1.64 to $2.25 each. I need a total of 6 o rings for the job. This seems spendy. Is there a cheaper place to get these o rings?

 

I guess nobody in here adjusts their own valves.

 

Take your stock o rings down to your local Lowe's or Home Depot to match them up, they sell quite a few o rings. Also, if you have a farm store, one that sells tractors, they always have a ton of different size o rings.