What an abosolute muppet I am, I've kept checking back here for a reply only to notice now that there is a second page, *facepalm* Haha, sorry for the late reply So as a little test I tried my old exhaust back on, and I ran it down the road, and I had no noise, which was great. However, I could still feel like bike sort of jolting whenever I got to about 7000RPM and I couldn't go any faster, and as the bike was jolting due to instinct it forced me to slow down as it felt unsafe. I will try opening the filler cap and listening next time I take it out which will be after I've finished another job first, thanks for your help P.S yet again sorry for the late reply