Julian to answer your question. The different pump cam's changes the squirt duration, One color will make it a quick burst and another will make it a long steady stream. Another thing to look at is are you working on it in a garage or out in the open air? I have to jet my carb out in open air mine will try to loadup in garage because of air flow. I have seen engines that you can just sit the hood on and the engine will change just because of air flow.
Mark