Tuesday my brother installed an HMF on my Raptor 350. We had it running good but decided we needed to install slightly bigger pilots. We put it back to stock for now. I started it today and it does not want to stay running. Runs for like a minute and stalls. With the choke full it idles steady for a while and the rpm's get higher and higher until I back off the choke and it stalls and will not start again. I was thinging it might be the mixture screw since we only turned it out two turns and it should be a half more. Yesterday I started it and it ran fine when it was warmed up. Can anyone help?

 

You are most likely running LEAN, and may be damaging your engine! Pull the plug out......is it light or white???? If it is lean, don't ride it until you get the jetting right.......

 

The plugs black. It's not popping or back firing. Seems like it's flooding itself. After the first try I went out and it started right up and I took off and warmed it up and it ran great. I will probably adjust the screw to 2 1/2 turns out and see what happens.

 

Ok, we adjusted the screw to 3 turns out. It seems to be running a little better. I will try it in the morning, when it's cold, and see if it helped. I can't seem to find the stock setting for the mixture screw. Someone told me 2.5 out, but we tried that, but 3 seemed better.