Sohron has learned me that the bracket of the lower pipe is supposed to be at the inside of the frame eye and the bracket of the upper pipe at the outside. So, unhappy with both brackets on the outside of the frame eye, I have yesterday (re)fitted both exhausts left hand side, with the help of a friend. Thanks to Ashimoto I know how to check the brackets. The RH side was allright. BTW, I've noticed that most CB500/550s out there, have it wrong.
Sohron's description is very useful, but because he does not mention fastening the brackets to the mufflers, I have made an attempt for a full step by step guide, which can be used for new and used exhausts alike.
I recommend to consult Sohron's pictures in the process. They are brilliant.
Please comment and feel free to correct my English.
Assuming you have all parts on the floor next to the bike, this is how I would do it. In the following I'll concentrate on the left hand side.
1. Apply some copaslip on the threads of the 6mm studs (head) and test the nuts will turn smoothly.
2. Dito for the 8 mm studs at the mufflers and the 10 mm hanger bolt and their nuts.
3. Check the brackets are in good order and not bent (you may consult pics below, courtesy Ashimoto).
4. Smear some vaseline or silicone grease where the brackets will contact the mufflers.
5. Dito for the balancetube that is to be between the mufflers at the rear end.
6. Position the brackets onto the mufflers. Note how Honda designed the holes, so make sure brackets can still slide somewhat!
7. Have the footpeg* with its 10mm bolt and its (spring)washer** at hand.
8. Check you have removed the old gaskets from the head and insert new ones. A dot of vaseline will help them stick in place.
9. Semi hang in the upper exhaust in front, just like Sohron shows. With one hand slide the JOINT over the studs making sure the two collars – their flanges facing the JOINT - stay in the correct position. Leave it there for the moment and let the rear end of the muffler rest on a high enough pillow or mattress. This helps a lot. No matter how concentrated you are, there is a risk a pipe will drop. No problem for a new one. Dropping a used pipe however can loosen the inner rusted damper.
10. Semiposition the footpeg*, its 10 mm (spring)washer** and bolt.
11. Now, with one hand covering the front JOINT, so everything there will stay in place, raise the muffler's end and use thumb to push the 10mm hanger bolt into the frame eye, so it now protrudes the latter by 1 or 2 mm. Leave it dangling there for the moment.
12. Position the connecting balancetube loosely over the little pipe of the lower exhaust.
13. Now repeat step 9 for the lower exhaust. On the LH side this pipe will route behind the side stand.
14. Raise its muffler end and position he top of its bracket on the inside of the frame eye, while allowing the balancetube to fit the alining short vertical pipes.
15. Push the 10mm hanger bolt fully in and fit loosely the (spring)washer** and nut.
16. At front equally fasten the 6mm nuts till some resistance is felt. Then semifasten the hanger bolt. Semifasten bracket nuts.
17. Before fastening further, check everything is in the right position. Check all bolts of the oilpan are accessible from below.
18. Fasten the 6mm nuts in front a bit more, then the big hanger bolt a bit more, then the 8mm bracket nuts a bit more. Now it is time for a final check to see everything is in the right position. The balance tubes and oilpan bolts are indicators.
19. Tighten the 6mm nuts in front. Gently! Do NOT use a torque wrench! Then tighten the big 10mm hanger bolt. Tighten the 4 bracket nuts. Finally for the 10mm hanger bolt, you may use a torque wrench.
20. Fasten crosshead of the balance tube
(Sigh!) If only Honda had made the exhausts in two parts to be connected with a joint halfway. So headers and pipes in one and the wider mufflers as separate parts.
* Later models, like the K2 had angled footpegs.
** The various CB500/550 parts lists show the plain washer and the spring washer in different positions. I don't think it matters much where you fit them.
