Exhausted…

[loxley007]

Hi all, Im trying to fit my exhausts on my 79 CB750 DOHC limited edition.

Try as I might, I cannot fit the headers, the collars and the exhaust pipe joint together so that the joint is flush against the head. There is always a gap of around 15-20mm.

I’ve got pictures below to try and show how I am trying to fit it together.

Can anyone tell me what I am doing wrong? Have I got the wrong parts? Is this normal?

I’ve tried this over two or three nights with no success. Can anyone help out?

Thanks in advance.

Andrew

 

[mrtwowheel]

You dug the old gaskets out of the heads, then you used new gaskets, right? It's normal to have just enough threads of the studs sticking out to start the nuts. There will be a gap at the collar to head,, about 8 to 9mm when all is tight. There is no torque specified for the nuts. Basically you tighten them evenly to smash the new gaskets then tighten to about 15 psi by feel. Hope this helps.

Edit........your last picture with the threads sticking out looks about right. That's what it should look like.

 

[loxley007]

You dug the old gaskets out of the heads, then you used new gaskets, right? It's normal to have just enough threads of the studs sticking out to start the nuts. There will be a gap at the collar to head,, about 8 to 9mm when all is tight. There is no torque specified for the nuts. Basically you tighten them evenly to smash the new gaskets then tighten to about 15 psi by feel. Hope this helps.

Edit........your last picture with the threads sticking out looks about right. That's what it should look like.

Wow, thanks. Your description fits exactly what I was left with. That means I have it right. Many, many thanks.

With the old gaskets, I did miss that at first but the last image includes when I’d dug them out.

Thank you!!

 

[mrtwowheel]

There is no room to use a washer when starting the nuts. I like to use stainless nuts and then stainless acorn nuts to cover the rest of the threads that stick out, makes a nice cleaner look.

 

[loxley007]

There is no room to use a washer when starting the nuts. I like to use stainless nuts and then stainless acorn nuts to cover the rest of the threads that stick out, makes a nice cleaner look.

Good advice. Cheers.

 

[loxley007]

I managed to find a Motad 4 into 1 from Facebook Marketplace in the UK so fitted that today. I’m happy with the look and now need to finish working on the air box before firing her up.

 

[mrtwowheel]

Just to have any exhaust without patches and holes is a good thing. I took off an exhaust last fall that I thought was in fairly decent shape. When I removed the bracket at the rear peg to paint the bracket one of the mufflers fell off from the pipes.

 

[hmcy]

I managed to find a Motad 4 into 1 from Facebook Marketplace in the UK so fitted that today. I’m happy with the look and now need to finish working on the air box before firing her up.

wondering if you threw away the original 4-4??

 

[loxley007]

wondering if you threw away the original 4-4??

I still have the two sets of the original down pipes up until just after the join. You can see one in this image. They have cleaned up pretty good.

 

[hmcy]

I still have the two sets of the original down pipes up until just after the join. You can see one in this image. They have cleaned up pretty good.

yeap that looks like a thorough clean out!