Topic: Aftermarket exhaust flange assistance needed

[Cbguy]

So I picked up an exhaust off of marketplace that was off a guys '74 750k. I have the same bike. The exhaust that I picked up has a different style flange on it than the factory exhaust. I am trying to figure out how to go about finding the correct flanges for this new exhaust. I found some from an '80 CB on ebay which I attached a photo of, if the hole spacing is correct and the length of the shims is correct those would work but I messaged the seller with no response on dimensions. I also haven't yet found any aftermarket options that would work. Thanks for any help!

[Cbguy]

I don't know if the images are showing up.

[BenelliSEI]

I think what you need are the collars ( and finned flanges (4) from a 1977/78 cb750K. They look like your second pictures but those collars look too short to me. Also use studs not bolts.

[scottly]

Do the new pipes have a flange like this? If yes, you need the K7/K8 parts like Benelli suggested.

[Cbguy]

Here is a pic of the flange out of the bike. Looks like the 77-78 collars will work. Now I'm wondering about the "joint collars" that go inside the collars to press the header flange against the head. I found these on cycle barn but $24 a piece x8 would be pretty crazy. I also read on a facebook forum of somebody not reusing these after they installed aftermarket exhaust. Thanks for your help!

Cycle Barn: https://oldbikebarn.com/products/cb750f-75-78-cb750a-76-78-cb750k-77-78-exhaust-pipe-joint-collar?variant=46946268348571&country=US&currency=USD&utm_medium=product_sync&utm_source=google&utm_content=sag_organic&utm_campaign=sag_organic&srsltid=AfmBOorFWO93kKCtWfiXkWur80RxLAc1C9xzbv_LJJ9EM0DYo7P8BW2O670&com_cvv=8fb3d522dc163aeadb66e08cd7450cbbdddc64c6cf2e8891f6d48747c6d56d2c

Facebook forum: https://www.facebook.com/groups/HondaCB750/posts/9204974396274879/

[BenelliSEI]

I may have a set. Will be in the shop Wednesday and have a look.

[Cbguy]

Thank you, Benelli!

[BenelliSEI]

I have 8 of the finned hold downs but none of the 1/2 shells.....

[Stev-o]

I also read on a facebook forum of somebody not reusing these after they installed aftermarket exhaust.

First off, welcome.   Secondly, I would not take advice from fakebook!  I've seen so many questions answered incorrectly that it just confuses the poster even more. You have come to the right place for correct answers.
And finally, I dont care to buy parts from OBB, very expensive.  There were co many CB750's manufactured that good used parts are still out there. Looks like Bennelli will hook you up, I can vouch for him.

And PS. be sure to remove the brass exhaust gasket from the head after you remove the exhaust [sometimes hard to spot]. These are not reusable, you'll need four new ones...

https://www.ebay.com/itm/394371549192?_skw=cb750+exhaust+gaskets&itmmeta=01KKYC287WD2WSWC0BTEV5XYX7&hash=item5bd2604808:g:qekAAOSwLUdjkqlP&itmprp=enc%3AAQALAAAA8GfYFPkwiKCW4ZNSs2u11xAPcxZsKyRwcBNnps4Zg93uyaR2Nt3RB%2BeGWV06561MOtb5w5H5oR5mIPe9te8oABFaZg80m%2F8y2U%2BFwTrNVbR7lW1VS8%2Bd2JndzGuvGu7p8dKj2N6yxLMo8yVduGssW0mFo2F9y5PMZ2V%2F87ufBJoVRSlls9POcj7%2BEodvSY2BiJnBLiNUd3hb0jnTOJ2V6CIImPST49Xhwv%2BJj%2BHJCzeEdJVKDsdIKDMhghp0QXdQQmdoot1Ch6jkpywbaV7REu6TwJOcu8pOghm%2FaP8szRJWaQTwqe03F63p9d3OWzuYzA%3D%3D%7Ctkp%3ABFBM0oWJzJ9n