Topic: Kerker header install help

[jg98445]

I just bought a 76 CB750K6 and the guy threw in what he said was a Kerker exhaust. I tried to install it using the stock split flanges but they don't fit around the pipes. Are there different sizes? Could these be the wrong pipes?

[Queeg]

my kerker headers are noticably larger than the stock. i know i have to play with the #2 cyl pipe to get it in but all the other pipes fit right in.   i dont have any split flnges on my 76 550

[Alan F.]

The Kerker I have on my 750K3 uses the exhaust spigots and clamps, I had to shim the clamps with a layer of beer can to seal them tightly.

[jg98445]

ttt

[jg98445]

my kerker headers are noticably larger than the stock. i know i have to play with the #2 cyl pipe to get it in but all the other pipes fit right in.   i dont have any split flnges on my 76 550

the pipes are definately a little larger and i don't really have too much trouble fitting to the head. I just need to figure out if there was supposed to be a different size split flange? Maybe i can yuse the earlier clamp type spigots?

[Inkscars]

My kerker was too big for any gasket. the pop can may be a good idea.

[Alan F.]

Maybe i can yuse the earlier clamp type spigots?

has anyone read my response??  Spigots and clamps Dude, Split clamps are not part of the spigot system, they came later on.

the pop can may be a good idea.

Ah, I see someone has. Crisis averted.

[Inkscars]

You had the same thing with yours alan?
It's way too tight for anything else... did you jb weld them on there or just wrap it?

[Alan F.]

My Kerker was on the bike when I got it, but the muffler was mounted too high and the headpipes were cocked downward too much.
When I mounted it correctly I couldn't get the clamps to seal (old style ring clamps with one bolt clamping them, I think they're original with the spigots)
So I cut a 3" by 1" piece of beer can and folded it in half lengthwise, so it's 3" by 1/2"  I made four of these, then I held them on the head piped and bent them to the correct curve.

When the header is clamped in place, but not sealed, I loosened one clamp at a time and slipped the shim under the clamp until it was not visible, then tightened the clamp.  Repeated four times and no leaks and the clamps now aren't as tight as they'll  go, there's still some slack in there for tightening later on if I need to.

[GAsohc4]

Hi I'm new here and this is my virgin post...I had the same problem big clearance issue trying to fit a larger header (mac 4-1)
on to my '78 750k

Problem: Header was considerably larger than stock thus the stock split flanges would no longer fit in the head with the header and do their job sealing the header against the exhaust gasket / head. Collars would not fit the the finned collar with the new head pipe diameter either

Solution: First cut the lip off the the first part of the collar the one that fits in the finned collar piece with the new large head pipe(s), then cut the outer most piece of the collar till its stepped down to half its original thickness but be careful not to cut through the second piece otherwise you'll have nothing. generally I'd cut as far up the collar as possible as to allow the collar to seal the header to the head without obstruction, but don't cut into the  spot welds they're the only thing holding the two pieces of metal together should be about 3/8" up but judge by the spot welds as to how far up you can go
sorry no pics...I'm not taking the exhaust off unless I have to.. it will need coaxing to fit up properly but watch for split collars getting hung up on the head. split collars not fully seated in the exhaust well, when tightening the the finned collar will crack the head

hope this helps, use your best judgement tho (I'm new to cb's)

[jg98445]

Thanks for all the input!
I think I'll try modifying the split sleeves or making new ones from exhaust pipe tubing. I cut one apart and found the outer piece fits well when install upside down, but may be too short.
To be continued...