The WR’s way overdue a valve spacing check, and I’m fairly sure they’re out (since it’s so bloody hard to start). I’ve never needed to buy shims before, everything I’ve had that’s needed adjusting has had those nifty adjustable rockers.
It looks like this sort of thing makes the most sense:
(it’s a 2003 WR450F), since I can’t really be arsed to strip it, measure the things and then wait for just the right sizes to arrive.
Is there a better (UK-based?) thing to buy? Would this be cheapest/easiest done by just giving it to someone else to do? Presumably valve shims aren’t really engine-specific and I just need to get some in the right diameter?
What you need to do first is check the valve clearances. If adjustment is required use one of the online calculators such as http://www.agbuzz.com.au/valve/valve_intro.htm or do the maths A = (B - C) + D where
A = new shim thickness
B = existing valve clearance
C = mid point of recommended valve clearance
D= existing shim thickness
Then order just the shims you need.
To accurately measure the valve clearances and existing shim thickness you’ll need
Yeah, I’m not really concerned with the process of measuring them and I know I’ve got the tools, I’m just trying to already have all the bits I’m likely to need before I start dismantling it.
And, I’ve only not waited to ask Matt because it doesn’t seem right given that I’m not realistically going to the OMC to do this.