So we finally had a chance to Fire-Up my Daughter’s kart the other day. Not a true test as she just putting around an empty parking lot, but it got me thinking about jetting. I had the sense to pick up a set of pre-pin gauge measured jets when I first started restoring the kart. My Dad sent me his Air Density gauge to use for deciding when to change the jetting up or down and I understand that when the gauge drops, so should the jet size.
My question is what is the percent of change in Air Density that would warrant a change in Jet size? It seems every jet manufacturer has a different flow rate for a given jet size and I have not been able to find any information on the Dellorto Jets. The set I bought for it came Numbered/Pinned Gauge measured 57/0.024, 59/0.0245, 61/.0250 and 62/.0255. My understanding is a 0.026 is a No Go. I also understand that any Jet change will be Relative to whatever Base Line is established for this Engine and Carb combo and one could assume that each step in jet size would yield a similar change in fuel flow percentage (example going from a 56 jet to a 57 would be a 3% increase in fuel flow rate).
Is this even possible to know without a Dyno and Measuring equipment?
Is there a ballpark number that can even be assumed from one jet measure to another?
Thank you in advance for any tips or advise.