Hi i changed oil and filter on ltz400 silkolene super4 10w40 i filled up the tank in front with 2.2 litres and started for 5 minutes then dipped check oil and topped up a bitt,now i started bike today week later and left tick over for few mins then held trottle at quatre open and it started to like miss a beat like a small knock that i could find coming back true trottle,,only since oil change and it doesnt do it all time worse at start not as ofton now...it has new timing chain bout 10 rides aand piston and bareel under a year ago ,also just got shims done few weeks ago,anyone help here im afraid to drive it incase do damage.thanks