Pop off settings and rich or lean

[itsmarta]

I have a 93 xp with a new SBT 657 engine. I also got the SBT carb rebuild kits. What pop off pressures should I get on the twin carb setup and should the pressures be the same in both carbs (PTO carb versus MAG carb). Is it better to have a low pop off pressure than a high pop off pressure. I heard a low pressure would lead to a lean condition by sending the fuel back to the tank versus supplying fuel to the cylinders. thanks

[Bill O'Neal]

Someone told you wrong. A low pop off will send more fuel to the motor, not the tank.

The 38mm Mikuni carbs need high PO pressures to make them function correctly with an OEM air box. Anything over 30psi up to 40 psi PO pressure will work.

Both carbs need to have equal PO pressures.