As we know,Cummins engine is famous for its reliable quality and reasonable price, most of our customer perfer cummins diesel generator set. However, sometimes we will come accross engine speed which is not stable, so we need to do follwering things for checking:

Firstly we need to check the fuel supply, because when the fuel supply is not regularly, engine could not run well which will lead engine lower speed and sometimes cause engine stopped.

After that we can check cummins engine speed controller, there are two type of speed controller for cummins engine, please check blow photos:

With this model, we can adjust STAB & GAIN to make engine speed in righ RPM.  The other model is speed controller with GAC, like below photos.

For such speed controller, we can adjust STABILITY &GAIN to make engine speed normal.  If adjust the engine speed controller can not make engine RPM well, we suggest to contact local cummins engine technical support.

If you are in need of Cummins diesel generator set, welcome to visit our wetsites www.top-genset.com  for more information and contact us freely!