CSMNL Exhaust for CB550 K3

[McCabe-Thiele (Ted)]

If you don't want to use a die.
Find a spare  nut of the correct thread. Cut a slot on the inside of the nut, Run a bolt into the slotted nut, grease nut.
Use the nut as a die.

[taysidedragon]

Have a good look inside the threaded nut, there may be a bit of weld spatter blocking the bolt.

[Oddjob]

Run a tap down the nut and a die down the bolt.

[Gromitdog]

Thanks Guys for all your replies I am out in the garage this afternoon so I will look at the stud and hopefully it get it sorted 🤗.

PS Nice to see your back on line Ken hope your improving as the weeks go by ? look forward to hearing from you when your up & about 👍

[taysidedragon]

Hi All
As I mentioned on yesterdays update on fitting my K3 exhuast system which other than a bit of filing on the rear main brackets it should be good to go for a final fit tomorrow 🤗 🤗  However the outer exhaust which has 1x 10mm nut and a location pin I can't seem find a nut to fit it 😞 I have put a thread gauge on it and it seems to be  10 x 1.25mm it will only go on 1/2 a turn before  feeling like its cross threading The thread has been chromed which might be the cause of the nut not wanting to go on correctly.

Any thoughts please

Is it a captive nut welded on to the bracket or a bolt that's causing the problem?

[Gromitdog]

The afternoon update I have spent the afternoon out in the garage and I have sorted the problem with the outer exhaust pipes 🤗 If I use the correct threaded 1.25mm nut guess what they go on NP "What a Muppet" 😖 😖.

Both outer exhaust are really tight length wise with little or no adjustment / movement to get the exhaust pipe flange to sit nicely onto the copper gasket , So maybe I am going to have to do a bit more filling on the main rear bracket to try & get some movement at the cylinder head end.

The split collars seem to long to be able to get the outer finned collar to bolt up as there is very little thread left. I have checked the part N0s of the split collars and from what I can see they are the same P/No for a K3 or a F1/2  I can see why this item comes with NO INSTRUCTIONS 😂

[Ken4004]

I had a similar problem getting my Cb400f exhaust to fit just could not get it close enough to the engine though as you did that  the split collars were too long , the mistake I made was trying to fit the exhaust with everything done up too tight.
I therefore loosen everything off and then tried again and with a lot of patience I all came together , when everything is loose there is enough flex in the down pipes to get it to fit together.

Do you have the original pipes ? I did and when I couldn’t fit the new pipes I tried to fit the old ones and had the same issue.

There is a utube video by CSMI showing how to fit the cb400 f exhaust which might be helpful , of course they guy does this job all the time so makes it look easy.


Good luck regards Ken4004

[Ken4004]

I just remembered I also unscrewed the studs a little way out of the engine to help get the first nuts started, be careful to leave enough thread in the engine otherwise you may strip out the threads in the engine, y
Then just a process of slowly tightening everything bit by bit .

[Gromitdog]

Hi Ken

Thank you for the update on how you fitted your exhaust system unfortunately "Muttely the Honda" came with a lot of parts from other series of 550 fours fitted and it had a 4-1 system fitted to it, Its has been a slow process to put on all the correct parts back onto "Muttely". Not much left after we got exhaust on 🤞

[Gromitdog]

After a afternoon of filing the 2 main brkts  managed to get all 4 exhausts on both sides so they had some movement managed to get the half collars on and the finned collars on and nuts just on by a thread or two although N0 2 exhaust is not showing any thread on one stud (Changed this stud) so it may be shorter did buy 6x40mm ones have left the exhaust just nipped up over night.

Will need to strip down again and touch up paint on the brkts before final fit I noticed on Wemoto they where selling 6x45.5x1 mm studs wondered if that might make it easier to fit as the nuts would have a couple of mm more thread to start would help

https://www.wemoto.com/parts/ae4673?srsltid=AfmBOoqLLLun2rt3DFzjpvvt_uRheFRB2Z7RJtKHTZWLd32VPBPffPnR