I have just installed a HPD pipe and clutch kit to my 400 Scrambler. The kit came with a 250 and 260 Main Jet. The stock carb had a 250 in it, and the chart recomended that I install the 260. This is fine, but then I had an item marked PJ. I assume this is the Primary Jet. The stock one in the carb was a 35, and the one with the kit is a 30. With the new pipe I understand the need for more gas through the larger Main Jet, but why the smaller Primary Jet??

Can anyone help me?

TheJoka
400 Scram

 

The smaller PJ is to clean up the low end bog that you might experience after changing the pipe and main. I went back to the 35 after hearing some pinging on hot days or when running lower octane gas and it still pulls very hard.
I'd start with the 35 jet and see if it falls on it's face or hesitates any, Then switch to the smaller one only if you have to. Good Luck