Excuse my getting off topic, but why are people using the long pilot jet? I recently did Dave's mods, desmog, desnorkel and unifilter on mine on mine and once I found the right jet size it runs so perfectly you'd think it was fuel injected. I still have the stock muffler. I'm at 5,000+ feet so I'm only using a 52/155 combo. When I was too rich on the pilot jet with a 55 it caused a problem at full throttle higher up the rev range not coming off idle, so based on mine I wouldn't suspect a pilot jet issue for you.