HondaCB650

http://www.dimecitycycles.com/vintage-cafe-racer-caferacer-bobber-brat-chopper-custom-motorcycle-exhaust-parts-dunstall-reverse-cone-motorcycle-muffler-80-84051.html

Would that muffler fit in pair to the Cb 650?

If noone can provide a sure yes/no reply, you may make a dummy from paperboard with the given dimensions to see if there is a chance that they fit.
Guess you have the European Z-model which means RC03 frame, the alumina footpeg holders and the indirect shifter level at the bottom area?

Sorry but it was not in the way I meant. I can always get them to fit on the bike, but how well will they work together with a 650 cc engine?

Well, the size looks sufficient.

All right: there is some agreement here that the CB650 stock exhausts fit quite good the stock airbox and carb configuration and that this configuration is hard to improve with a single measure. As the low rpm performance of the CB650 is poor enough and the stock mufflers are reflection type, low rpm performance may additionally suffer or other power variations along the rpm range may occur with different mufflers.
So I would not expect an improvement if you just swap the mufflers.
I would think in the best case you would have quite the same behaviour with a bit different sound.

But finally you only will know for sure if you try it out yourself or find someone who already did it.

Well how the stock mufflers work i dont know as there was none mounted when I bought the bike.



Those mufflers that the bike was equipped with when I bought it would fit better on a HD as you can see.
If those i linked to works better than the ones i have mounted i rather go for the new ones.

If you are asking about how they would look on the bike. You would be a lot closer to the appearance of the original 4 into 2 exhaust.