I have a 2008 Raptor 700R, two months ago I bought a HMF slip-on pipe and a HMF Optimizer. Everything else is stock. I run the quad with a stock air filter with the air box lid off. When warmed up and running, the quad runs great bottom to top with no hickups or hesitations. The only problem I am having is that when I start the quad, it will fire right up and idle for a few seconds and then quit. Eventually after stalling out five or six times, the quad will stay running at idle. This doesn't happen every time.... But it does happen often. It almost always happens when I take a lunch break on the trails and go to fire it back up. I do not use the throttle when starting; I shouldn't have to with EFI. I'm not sure if this is related to my new pipe and optimizer or not. I run the exact settings that HMF suggests to run. I clean my air filter every two rides, I'm not sure what else this can be. Can anyone shed light on my situation?