GSXR750 Model L running strange at 8000rpm


New member
Oct 19, 2014
Hi guys, hope I have posted this in the right place :)
I have a GSXR750 1991 MODEL L, I had a few running issues recently as I was riding the bike, when hitting 4000-6000rpm I would hit a flat spot, after pushing through the bike would run its normal way. So I have serviced the bike, including swopping out the k&n filter for a standard and changed and gapped the plugs, now the flat spot has gone but when I hit 8000rpm the bike pops, bangs and farts, if i push it through to 9000 rpm it takes off like a rocket, as it should. Does anyone know what the issue could be please?? Thanks in advance