What caused this soft seize is unknown. This has never happened before and the bike has been running great for the past 4000 miles. Could my mid-range be too lean? I had installed the 50/160 slow idle jet which is on the lean side. I have in the past tried the richer 55/160 but the bike never ran good with it. The E1 atomizer is also lean but the bike did not run better when I tried the richer BE3. Then again, maybe an air leak occurred making the engine run lean. However, I did re-torque the two carb bolts to 11 ft lbs just 400 miles ago. Regardless, I must now find the cause and fix it. For starters, I will up the jets in the middle range and check the spark plug. As it stands now, my PX150 is not dependable for regular rides in the country.
If anyone has encountered this problem with their 2005 PX150s and has suggestions where I should start testing or jetting I should try, I would be most grateful.
US 2005 PX150 Vespa.