So I found a Yamaha 5-BN1 oem exhaust for 30.00 it’s brand new. The guy who sold it to me said he found it in one of his rent houses. He had no clue what it was for or it’s value. (Do I feel a little guilty yes) all he listed on the ad was the part number. It looks to be the same exhaust on my 650 classic. Will it fit right up or am I wasting my time? I know I could just try bolting it on. However I just replaced all the gaskets and got the bike back together. Even if it’s the right size if it turns out it’s off a 250 or something will I have to worry about back pressure or anything? I can’t find that part number (5-BN1) listed anywhere except for generic eBay ads for exhaust that list it for a 650 but that seem odd to me. Not sure what I should do.