Topic: CB750 exhaust installation - problem with split collars/header clamps

[ando]

Hi there,

Which way is the correct way to install my split collars? I have read here and other places that the flange on the collar goes into the finned clamp thing. But there is just no way it will fit on the bike that way. The bolts arent long enough.

Please see photos. Which way? What am I doing wrong? The first two photos show the flange pointing towards the engine, and this way I can fit the pipes on smoothly. The two other photos show the "correct" way according to some of you guys here, with flange pointing out from engine. This way there is no way to fit it.

Thanks 

[ando]

Oh, thanks man.

http://imgur.com/a/zfYj2 - This way the pipe fits on to the bolts. But I am told the split collars are fitted the other way around?

http://imgur.com/a/fQ7vR - Same way as above, but with the finned clamp thing on to of the split collar

http://imgur.com/a/IGmnm - This way I am told is the correct way. But there is nooo way the pipes can be attached to the engine like this.

http://imgur.com/a/JcDot - As above, with the clamp thing around it.

I did not install new crush washers, but ordered a set today.

 

[madmtnmotors]

What bike? Are we talking 500? 550? If so, then disregard previous post because I know very little about the little fours...

[ando]

Yea its a CB750F

As far as I know the pipes are original. Bike was running fine with all pipes mounted before I dissembled them to fix an oil leak. The collars just fell out when I got the bolts of, so I didnt notice which way they were fitted. 

 I have also noticed the "meat" on the flange you are referring to, compared to photos and videos of pipes from similar models. I was hoping this "meat" means the split collar goes on opposite of other, meatless, pipes.

https://www.cmsnl.com/honda-cb750f-1982-c-general-export-kph_model14872/partslist/F19.html#results

On the exhaust muffler schematic above it looks like an original pipe with "meat". And it actually looks like the split collars are fitted with the flanged end pointing towards the engine. Am I wrong?

[magnum56]

I think you have already correctly proven the only way possible to install those split collars on your bike.

And no, I don't believe you are wrong. 

[flybox1]

This IS the correct way to install the flange, but the 'spacer' is not supposed to be there.
grind off the solder/weld

[danyo]

I believe your Cb750 F is DOHC. If that exhaust was on your bike before it has to fit now. I have NOS  Kerker header for DOHC bikes and it also have that extra meat.
It's clearly visible on cmsnl.com link that you do it correctly on first picture.

[madmtnmotors]

Silly me, this was posted under "SOHC/4 Bikes". Can't help you with a DOHC... 

[flybox1]

DOHC?     Fooled me....

[ando]

DOCH SMOCH.. Cant we all just be friends? 

Nah but seriously thanks for the help! I trust I did it correctly the first time, as the schematic is showing.

[madmtnmotors]

DOCH SMOCH.. Cant we all just be friends? 

Nah but seriously thanks for the help! I trust I did it correctly the first time, as the schematic is showing.

Most certainly! We all enjoy the ride, no matter how many cams. The front right motor mount is what made me question what model/displacement we were talking about. I just don't have any hands on experience with the DOHC models other than the knowledge that a 79' DOHC CB750 swingarm can be made to fit an earlier SOHC CB750 with a little trimming.

From what I've seen it looks like the later model DOHC exhaust collars are indeed reversed when compared to the earlier SOHC models. We do have a section for "Other Bikes" where discussions are open to any make/model/year which is where this thread has been moved. Good luck with the project!