Ragz,

Why are you checking Google for engine timing?

You can find that on the link you were give for RC Showcase, or on ZDZ's website as well.

Wayne's got a good point, when the stops are removed on these carbs for RC use it is quite easy to get the throttle butterfly turning the wrong way and the engine will be hard to start, unreliable idle, poor transition, etc. because the low speed fuel circuit cannot function properly if the throttle plate is turning the wrong way.

It's a pretty common problem and Wayne's not the only one who's done it, timing can be an issue as well but not enough to cause the problems you're talking about if it's only a question of whether it should be 5mm or 7mm and I do think all the 40's are 5mm...