I just installed a 27 tooth sprocket on my 1999 Tomos Targa LX. I had to remove the oil pump and a thin washer and rubber seal and a metal conector to the magneto to the oil pump. I think i got the washer or the rubber seal or that connecter in a different order b/c it is making a larger noise than before I installed the sprocket. But I do know it is defiantly getting oil and is pumping. So could anyone help me please!