The reason I'm writing this one up, is because I had heard about this modification, but it took me a while to find out how to do it. So borrowing from the tribal knowledge of many who came before me, here it is.
There is a space above the jets on the Spaco / Dell'Orto carb which is covered by the air cleaner. This casting has a recess in it that is positioned directly over the top of the jets. By allowing direct flow to the jets with the provided holes, the difference is amazing. I don't have a dynamometer, but my "standard test hill" is the proof. I increased one main jet size and was able to take on the test hill with cooler temperatures and 5mph faster than before. This is the easiest and most beneficial modification to the 2T engine.
With credit to VespaLabs, here's the difference in the original and drilled air cleaner.
This modification altered the jetting :
DR177 and SITO+ Stock 20/20 carb 48/160 idle, 160 air, BE3 atomizer and a 107 main jet. Drilled stock air filter frame stripped and replaced with UNI foam.
Mix Turns = 2.0
No comments:
Post a Comment