What level's your Gyarados? For me, I had trouble with Noel as well and was greatly underlevelled. But I managed to beat him by slicking Leech Seed and Sleep Powder on that Cincinno with Jumpluff and Gourgeist, then proceeded to Dance and sweep with Gya. You should try it if training/grinding up other Pokes might be troublesome. Also, you can Knock Off (Hariyama) that King's Rock he has to avoid the likely flinches he might get.