What jet size

Just put on a 4 into one pipe and pod air cleaners on a 1978 KZ650 sr. Was wondering what size jets I should be using in my carbs?

There were 2 versions of the 1978 SR models, also known as the D models. There was the D1 and the D1A models. The D1A came stock with smaller carbs (vm22) and smaller main jet (90)
While thte D1 came stock with vm24 carbs with a 102.5 main jet.There are also differences in the jet needle and needle jet used stock on the models as well as differences in which type of adjustment screw (air or pilot/fuel). 

As to what jets you need for the changes you have made, I would suggest you check out Zed's air corrector jets for use with pods.


 

Whatever the stock jetting for your bike was leave the pilots the same, increase the mains by one size and fit air corrector jets to the pilot main jet intake port.

Not to nitpick but as I understand it the air corrector jet is placed into the main jet air jet location and not the pilot jet air jet location.

gd4now wrote:

Not to nitpick but as I understand it the air corrector jet is placed into the main jet air jet location and not the pilot jet air jet location.

Yes! They go in the main air passage to the needle jet / emulsion tube.