Reply To: Front cylinder not firing – GT650 Jan 22, 2026 at 10:28 PM #21767 Mark de Rooy👤 Member🖊 Topic Author Topics: 5Replies: 64 Hi Marcel, it was the front cylinder. I tested the cap, it seemed to be working intermittently if that’s possible? Anyway I had another lying around and fixed it. I will change them to ngk soon.