Ran the full mod EXTECH 2 .21 with 053 pipe at ET Motopark in my truggy on Sunday and the thing just rips. I had to go to 1.1 springs because the motor wanted a little spool time but after that it was Dialed. I got 4th at the Day after Supercross race at ET behind Maifield, Peck, and Jerell Grey. The track has a 120ft straight and no one pulled me. I talked to ED and he told me to run the P4 plug. The motor went the 6min in qualifing and still had a 1/4 tank with the stock restrictor, with a little work I will get good fuel mileage.