Topic: Exhaust swap from ‘76 to ‘77

[la ca fe]

I’m going to put on a set of ‘77k stock exhaust pipes on my ‘76 cb750k. I found them hanging in an old abandoned barn here in N. Carolina that is getting ready for a developer to tear down to make room for “progress”. The guy who took them off of his bike must have done it the day he drove his new bike home to his farm from the dealer. I cleaned the up and have yet to see a set so perfect! With a simple modification, I can run them on this ‘76k I have that needs an exhaust.

I have stock carbs and airbox my ‘76. Will I need to change any adjustments to my carbs to accept these ‘77 pipes?
Anyone here done this before?

Thanks!

[MauiK3]

I'm sure others will chime in, I suspect some sort of jetting or needle setting will be needed.

[newday777]

Congrats
You probably won't have to rejet but you won't know until you get them mounted and do some plug chops to be sure that it's burning properly.
You will need to make some rear mounting bracket modifications as the 77 has a longer frame than your 76 and earlier K frames.

[PeWe]

Plus the -77 stuff with studs etc attaching the pipes to the head. Not old style spigots as K6 had stock.

[HondaMan]

Like PeWe said: those K7 pipes mount differently. They will likely be fine with the jetting you have: if the plugs run a little bit dark then turn the air screws inward a little, like 1/8 turn. The K7 has PD style carbs for emission control reasons, and they mix differently (especially during deceleration), so those pipes were designed with a bit more restriction than were your original pipes - to go with those PD carbs.

[la ca fe]

Thanks for the comments and info, looking forward to getting started.

[Kelly E]

Thanks for the comments and info, looking forward to getting started.

I like your KFC bucket. I have the Colonel himself. I got him when they closed down the KFC nextdoor. They were going to throw him away until my buddy and I rescued him from the demolition dumpster about 2am after tequila Tuesday back in the early 80's.

[BenelliSEI]

Let us know how this turns out. I have a good set hanging outside my shop and keep “wondering”. Do you have the plates that tie the pipes to the rear foot pegs and frame. Pretty unique part!