I ran a set of Fast Eliminators on a 97 MXZ 670 for two years. If you are a good tuner or get a good setup they are OK. I ran the twins with .8 base , head shave to .065, 150-80 RV with K&N's, short boots 410 mains @ sea level. For clutching I ran 145's , 17 grams, 200-320 and a 50 deg @ 16 pounds. Was very fast with an 1 1/4 . Mine liked to spin @ 82-8300. They were temperature sensitive and were the ####s in deep snow if you had an egagement of less than 4000 due to a loss of bottom end. When they work , they work and when there off their a dog.
Fast twin Eliminators are good pipes for the 670. I ran them in a 95 ss. My setup was similar to H.O. rider's. They were good for a few M.P.H. I ran 25/44 gears and 168 studs. I also think the stock pipe is very good. Talk the guy down on the price. If you're willing to spend some time tuning you will see good results.
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