exhaust collar / flange differences

[plankspanker]

Hi everyone. Seems apparent that there must have been a change to the finned exhaust collars when the CB77 exhaust system changed from two piece to one piece. I am assuming that the diameter of the hole was increased so that they can be slipped over the flange on the header. The hole on my early collars measures ~40mm. Wondering 1) am I correct about the change and 2) if so, what is the diameter of the hole on the later ones? Thanks!

[mike1969]

Don't know that they make different flanges for one piece exhaust. I purchased a pair of NOS one piece Dream mufflers and found the only way to get the flanges on the exhaust was to bend the lip of the header pipe. I took a very small pair of vise grips and slowly and evenly bent the lip of the header until the flange would fit over the end. After I got the flange on I slowly and evenly bent the lip back into place and used a flat mill file to take the high spots off. Works perfectly.

[48lesco]

The collars and flanges are both different. The late flanges for the one-piece system are a larger diameter to fit over the lip on the header pipe. The late collars also have a lip to engage the collar. Part numbers are in the online fiche:

http://www.motogrid.com/pages/OemParts? ... F14268S09A