Im kind of new to the jetting scene. I just picked up a used Yoshi full exhaust system on ebay for the bike. Along with it came 2 jets, and a needle. However the seller said he never installed the pipe nor used the jetting/needles so he is not sure if the jets/needles go with the pipe. Now instead of plugging and playing and seeing what works, how can I find out if the 2 jets and needle he sent go with that full system exhaust ? Also, I live in the northeast and the temps now are in the 30's. So regardless of whether or not the jetting is correct the bike will still backfire alot due to the cold. Are there any other predictors to determine if the jetting is correct ? Thanks.