The 1971 DT1E-MX was the last Enduro conversion for yamaha. In 1972 they came out with the DT2MX and it was all MX. I had one and raced it for several years. It worked good on the track, but didn't have enough flywheel for trail riding. The DT2MX had a reed valve engine and The DT1-EMX had a piston port engine.
Any fool can criticize,condem and complain and most fools do. Ben Franklin