As mentioned the tappets were quite loud compared to what they should have been, so when we took the head back off we then re-set the valve clearances correctly..this really reduced the sound down although there's still a noticeable faint tapping sound. Over all it sounds much better. Here's a pic and video. https://youtu.be/mwrQdM6ADLs Excuse the dirty looking oil on the pic..we only topped it up a little bit and left the other oil in there....that happens to be about 5 years old Luckily I managed to grab a heavily reduced bargain at Tesco for some Mobil racing motorcycle oil..probably a bit overkill for a CG (given that they can run on olive oil lol) but heck it was only £2 reduced from about £18..couldn't pass on that one!! [mention]fastbob[/mention] I agree on the pod filters...I've got my doubts about them, the original air box isn't the prettiest but it seems to do a very good job, just a shame about the size of it, the pod filter will sometimes make the engine cut..I imagine it's needing more fuel given the huge increase in air it's taking in with it. Raise the needle? Bigger main jet? I will note that it isn't the original carb, we got rid of that one in favour of a single cable one.