Topic: Need Some Advice (Exhaust, jetting, etc)

[RainsongCB750F]

Okay guys, school me on some things. I have a 78 750 supersport, stock everything, I want to remove the stock muffler and put on a 12inch stainless cone muffler. Question1.) Will that work? Can i just pop off the old muffler and slip the reverse cone on? Question 2.) My guess is that the cone muffler is less restrictive than stock therefore I will probably need to rejet, am I correct? If so, what size jets do I need?
I know there are a thousand jetting questions, but I just want an organized response instead of looking all over the place to piece together the answers to the questions.

Thanks guys

[70CB750]

From what I understand, the motor is much less sensitive about the muffler than the airbox.  There is a good chance it will work without rejetting.

I have a 78F motor in my project with rebuilt head, 4 to 1 Cyclex headers and 18" reverse cone muffler.  I left the jetting the way it was, I may need to move the needle or such, but I will start with the stock jetting and see.

[evanphi]

If you're going to a completely open header and muffler (which it sounds like... most shortys are open), you'll probably need to either raise your needle one clip, and/or increase main size, not to mention your air screws.

From what I understand, the motor is much less sensitive about the muffler than the airbox.  There is a good chance it will work without rejetting.

I have a 78F motor in my project with rebuilt head, 4 to 1 Cyclex headers and 18" reverse cone muffler.  I left the jetting the way it was, I may need to move the needle or such, but I will start with the stock jetting and see.

What Prokop said is correct, though. Start with stock. You may not need to change anything since you have the stock airbox. A slightly baffled reverse cone (such as the gaining-in-popularity 18" quiet core from Cone Eng), maintains a bit of back pressure and won't lean out the tuning too much.

[RainsongCB750F]

Okay great, thanks for the responses guys. Ill start with stock and see how it feels. The bike runs very strong right now, so if I change the muffler and notice a difference then Ill know what to change.

Thanks again