had problems getting home on last ride.after 2 hrs of stop and go riding i started the quad and i cud tell it wasnt running right..managed to get back to truck,but very little power and had to continuisly snap trottle all the time..if i kept it trottle still, engine wud die,but with motion it wud keep going,top speed about 15-20kms and with backfiring..looked at plugs after getting home and heavy fouling and still working bad...just bought second hand ,so not sure if any recalls done.......any suggestions where to go from here..ck'd the tps wires and sensors,cleaned plugs and changed gas in case water present.....tks

ron