Successful 2-1 MAC exhaust with pod filter carb jetting

[JSak]

I just wanted to share my *final* carb jetting for others interested. I have the after-market MAC 2-1 exhaust, and small round pod filters shown in the picture. This is for the 1980 XS400G model.

I have the pilot screws turned out 4.5 turns on the left, and 6 on the right cylinder. I may consider bumping the pilot jet one size in the future, but if it works why fix it?

The needle jet has 3 washers as shims, which I think is equivalent to 1 1/2 notches richer.

The main jet has been increased 3 sizes from factory (135), so its now the 142.5 jet.

The bike pulls smooth from idle to redline without any stuttering or hesitation. Hope this helps somebody

 

[redratbike]

wow someone who got it right well done

 

[dO-bOy]

very interesting! i have stock exhaust and uni filters so i'm really interested how rich you run it with the pilot screws and stock pilot jet. it is a note though that i'm running a '79 which comes with 132.5 and 42.5 main and pilot jets respectively

 

[drewpy]

good info, that will be helpful to other peeps

 

[jigm400]

just for entertainment 80 xs400 45 pilot 145 main 1 needle spacer, uni foam pod filters, and full custom exhaust w/ baffles... runs amazing in the summer and like a raped ape in the winter.

 

[skillzman1]

awesome...I haven't worked on my bike in a year...the carbs and jetting science was a stressful thought that was slowing me up ....now I look...and somebody did the hard part for me...now I just need to get the pieces and get at it.
would you recommend the pilot jet step up in size?