{"product_id":"spark-exhaust-db-killer-moto-gp-40mm-open","title":"Spark Exhaust dB Killer Moto GP 40 mm Open Universal G9973","description":"\u003cp\u003eForty millimetres through the middle — five more than Spark's other two Moto GP inserts, and the reason this one exists.\u003c\/p\u003e\u003ch2\u003eKey Features\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003edB killer for Spark Moto GP silencers.\u003c\/li\u003e\n\u003cli\u003eØ 57.5 mm outer, 40 mm internal bore.\u003c\/li\u003e\n\u003cli\u003eOpen type, no perforation.\u003c\/li\u003e\n\u003cli\u003eThe least restrictive of Spark's three Moto GP inserts.\u003c\/li\u003e\n\u003cli\u003eStainless steel, removable.\u003c\/li\u003e\n\u003cli\u003eSpark part number G9973, made in Mantova, Italy.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eForty Instead of Thirty-Five\u003c\/h2\u003e\u003cp\u003eThe step from a 35 mm bore to a 40 is larger than it reads. Flow area goes up by about a third, which means this insert costs noticeably less power and takes noticeably less noise out than the other two.\u003c\/p\u003e\u003cp\u003eIt is the part for a large engine that would choke on a 35 — or for a venue whose limit is generous and where the only aim is to shave a few decibels off the top.\u003c\/p\u003e\u003ch2\u003eThree Inserts, One Case\u003c\/h2\u003e\u003cp\u003eSpark lists three plugs for the Moto GP silencer and they form a ladder. G9941 with twenty-one holes takes the most out. G9969, open at 35 mm, sits in the middle. This one, open at 40, takes the least.\u003c\/p\u003e\u003cp\u003eOwners who run the same machine at several circuits sometimes keep two of the three in the van. They swap in minutes and they cost less than being turned away.\u003c\/p\u003e\u003ch2\u003eChoosing Without Guessing\u003c\/h2\u003e\u003cp\u003eIf you know the reading your machine gives open and you know the limit at the gate, the gap tells you which insert you need. If you do not, start with the middle one — going quieter is a cheap correction, going louder is not possible once the session has started.\u003c\/p\u003e\u003ch2\u003eFitting\u003c\/h2\u003e\u003cp\u003eFrom the outlet, with the silencer on the bike, using hand tools. No dismantling of the link pipe and no removal of the case.\u003c\/p\u003e\u003ch2\u003eFifty-Seven and a Half Across\u003c\/h2\u003e\u003cp\u003eThe body diameter is common to all three Moto GP inserts. It is the bore that separates them, which means the three are indistinguishable in a parts drawer unless somebody labelled them — worth doing if you own more than one.\u003c\/p\u003e\u003ch2\u003eOrdering\u003c\/h2\u003e\u003cp\u003eOne per silencer, same article for a left-hand or a right-hand case. Tell us the silencer number if you would like us to confirm the bore before we ship.\u003c\/p\u003e\u003ch2\u003eLegal Status\u003c\/h2\u003e\u003cp\u003eUnchanged by this part. The Moto GP silencer is a racing article; an insert is a noise tool and not a certificate.\u003c\/p\u003e","brand":"Spark Exhaust","offers":[{"title":"Default Title","offer_id":53617781047562,"sku":"G9973","price":20900.0,"currency_code":"XAF","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0949\/7831\/0410\/files\/6290704025976_645b3e95-b410-486a-a54d-bf8273cf3d52.png?v=1788354053","url":"https:\/\/inter-pace.com\/en-cm\/products\/spark-exhaust-db-killer-moto-gp-40mm-open","provider":"Inter-Pace","version":"1.0","type":"link"}