Outdoor Power Equipment (Lawn Mowers, Snow Blowers, Chain Saws and more) Discussions

I ran into a problem while giving my snowblower a real workout here in MA.    After about an hour or so   the 1st gear and slow reverse lost most power  .the wheels would barely move!.   If I used any other of the 5 gears they worked fine  also fast reverse worked OK. 

the snowblower is a 1980 yardman with the 5hp tecumseh snowking.    it uses a friction disc type drive sytem. 

thanks for your help