Spanky Report post Posted February 6, 2020 Looking for some advice please. I've a 2018 250rr and I notice the odd knock when I give the bike a little rev (off the bottom, first 1/8 of the throttle). I was out riding it today with my son on his oset ( so just gently plodding hardly any throttle and at one point it startedknocking quite badly. I've read previous posts about lifting the needle up one. As far as I'm aware the needle is in the standard position. The bike never used to do this but I'm starting to notice it more and more. Many thanks. ? Quote Share this post Link to post Share on other sites
pauls320 Report post Posted February 6, 2020 Ooh..worn conrod bearing? hopefully its not already time for a rebuild Quote Share this post Link to post Share on other sites
Spanky Report post Posted February 6, 2020 No, its definitely ignition knock. Quote Share this post Link to post Share on other sites
2stroke4stroke Report post Posted February 6, 2020 (edited) Have you changed your petrol supplier recently? Edited February 6, 2020 by 2stroke4stroke Quote Share this post Link to post Share on other sites
Spanky Report post Posted February 6, 2020 No, same as always. Quote Share this post Link to post Share on other sites
faussy Report post Posted February 6, 2020 Probably dirt in your carb since its a keihin, causing it to run weak 1 Quote Share this post Link to post Share on other sites
sherpa325 Report post Posted February 7, 2020 This can occur on GasGas bikes as well and if it can't be cured by winding the air screw in a little, people generally go to a one size bigger pilot jet or a no3 slide or lift the needle. All have a slightly different effect and it seems to be a bit of trial and error as to what works for you. Also its important to do this after the bike has been decoked as carbon deposits on the head and piston can cause an increase in compression and add to the problem Quote Share this post Link to post Share on other sites
dwb5151 Report post Posted February 7, 2020 Well my Trs was doing this a few weeks ago turned out, to be the CDI box 1 Quote Share this post Link to post Share on other sites
Spanky Report post Posted February 7, 2020 1 hour ago, dwb5151 said: Well my Trs was doing this a few weeks ago turned out, to be the CDI box Well I hope that's not the problem ? Quote Share this post Link to post Share on other sites
