I'm rejetting my 450r this weekend and I came across Dynojets instructions on their website and saw where they say to install a main air jet plug. Is this needed? I haven't heard from anyone that said they did anything with this air jet. What is it's purpose, besides the obvious. Anybody got any suggestions???

 

I'm not real familiar with that carb. But the purpose of the "main air jet" is to bleed air into the main jet circuit, to break up the solid gas flow through the jet and mix with air...so it can go "bang". It leads to the "emulsion tube", right between the main and needle jet. Sometimes it's removeable and sometimes it's not. It's got lots of tiny little holes. I don't know why dynojet wants to plug it, are we talking about the same thing here?

 

I don't know if they are actually plugging it but that is what the part is called.