I have a Kubota B26 TLB that blow black smoke if I push it too much, is that bad for the engine? During normal snowblowing operation everything works fine but If I go a little too fast I can hear the engine tone change slightly, RPM are not dropping, and the black smoke starts to comes out. That's my sign to slow down a little. I could get the job done faster with the black smoke coming out but was wondering if its bad for the engine or not.