Topic: 4 into 1 exhaust pipe OD.

[Ace Blackwell]

Hello All

I’ve got a 1977 CB550F. I’m looking to buy a muffler.  I need to know if my pipes are stock.  I believe the actual pipes are but the transition piece that is welded on may not be. The bike was stolen many years ago. My nice new OEM muffler was removed and a piece of straight pipe was added.  Knowing the thieves, welding on a new transition piece seems beyond their capabilities.  But one never knows.

Knowing if I’m stock or not will help with the shopping.  I measure the OD at 2.12” and the ID at 1.93” (not that it may matter much)

Thanks
Ace

[jlh3rd]

i have a 75 550 F  nos muffler, the inside diameter measured with the packing gasket is 2 1/8 inches. So the outside diameter of my header collector pipe is within a few mm of that. The 75 and 77 header pipes are the same, i think the muffler is also so that measurement should be good.

[Ace Blackwell]

Thx jlh3rd.  That's what I needed to know.