I have a 450 with a HMF slip on, Uni filter, 45 pilot, 170 main, stock needle at #4, 2 turns out on the fuel screw and it's just not quite right. I want to leave the air box lid on. When the quad is idling and I smack the throttle it just dies when in neutral. It also does this if I'm in 1st or 2nd trying to take off quickly. If I click the choke out once it seems to clear it up. I know this typically reveals a lean condition, but where? Needle, pilot, main jet?? It also seems as if it may be fat on top. I haven't pulled the plug out yet, I'm going to do that now. I'm in Indy, In, which is about 650' above sea level. We are about 35 degrees at this point.

Can anyone help? I'm hoping to resolve this tonight! Any and all input will be greatly appreciated. Thanks!

 

changing the needle clip position is relatively easy and fairly quick.

I would drop down to the 5th clip position from top and try it.

If it runs better then you could adjust your main..possibly dropping down to a
168 but wait till you have the mid done.

You can also try after dropping the clip..turning your fuel mix to 2 3/4 turns..

I've not familiar with the UNI filter though.. so I am just trying my best to help.

Have you tried it with out the lid as a test to see what happens?