Dr Honda, thanks so much for the reply. I will get the kits ordered for the SBN38. Two years ago I went through the carbs, cleaned the jets and the filter screen, but I didn't replace anything. It helped but this year the XP800 is not a happy camper. I have been reading up on the pop off pressure and I checked both carbs. One carb goes to around 15 PSI and pops off. The other carb will not hold any pressure. For a needle valve of 1.5 pop off pressure should be around 36PSI - 40PSI at least that is what the book says. The fuel pump seems to be ok, I'm debating on rebuilding the fuel pump. Thanks Brian