Topic: '78 cb750 exhaust fit on a'74?

[canonball]

Did a quick search online with no luck, I'm selling the exhaust off my '78cb750 and I've got a guy with a '74 who's interested in it. I don't think they'll fit but I wanna make sure if someone else happens to know, thanks!

[bjbuchanan]

yeah they will fit. How it mounts up to the head is different tho. Your exhaust has collars and clamps, his will be a spigot style. Spacing and size is same. Sell the mount stuff to him or have him get it off ebay for like 25$

The only possible interference is if yours is an (f?) bike possibly. It won't be perfect but it will be pretty good

I have used an 80 DOHC header and exhaust on a 72 engine in a 76k frame. Just be clear that he will have to fab a bracket out back but the thing does "fit" tho

[kmb69]

I would say no. Besides the spigot issues BJ mentions, the rear muffler mounts on the 77-78 K's are significantly higher and use brackets that bolt to the inside of both mufflers. The 74 only uses the long rear foot peg bolt that goes through both mufflers. No easy solution.

[canonball]

Sorry, I should have been a little more specific. Yes I've got a K and it's the 4-1 style exhaust that I'm selling and not the stock 4-4, if that makes any difference. I was told a while back that the 77-78 and 79-80 had different motor angles and that the pipes would line up to the block right. I kinda figured this might be the case in this scenario, but I guess not?

[kmb69]

OK. The header part will work by removing the spigots on the 74, adding exhaust studs, and requires the 78 flange clamps and collars. The muffler bracket will have to be shortened or at least a hole drilled to line up with the 74 rear foot peg frame bracket.

[bjbuchanan]

Sorry, I should have been a little more specific. Yes I've got a K and it's the 4-1 style exhaust that I'm selling and not the stock 4-4, if that makes any difference. I was told a while back that the 77-78 and 79-80 had different motor angles and that the pipes would line up to the block right. I kinda figured this might be the case in this scenario, but I guess not?

No whoever told you that was full of it. I can definitively say, and show you pictures of my 72 engine with the 4-2 setup from an 80 DOHC. I had it on all winter til I got a 4-1 that I rly wanted. You have interference issues with the kickstand and minor with the brake pedal with the DOHC exhaust because it is designed to hug a different frame. Port spacing is the same

An aftermarket 4-1 will fit you just gotta use the right attachment setup, whether you choose spigot or stud/flange/collar deal. It is more of how the exhaust is designed, which setup it uses

[bjbuchanan]

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There you go. It works it is just fiddling

[canonball]

Cool thanks for the info guys, got it sold, we lined up the exhaust with his bike this week and looks like it won't take much to get it on there.