Hi There. I ust picked this rig up with 48" plow. It has the 26hp B&S engine and runs well. When I start it goes good in forward gear with power and speed, but is slow/weak in reverse initially. It then loses reverse. If I leave sit for awhile it will repeat above. I've followed procedure in manual suggested to purge air, but to no avail. Temps. were about 25 degrees here in Maine late afternoon today. What's my next move.... drive belt or check/add 20w-50 fluid through vent tube? Any thoughts or experience with this would be greatly appreciated. Cheers ~ Bob