The engine speed is unstable, and it is often referred to as “travelingâ€. There are two main reasons for the occurrence of travel: (1) The governor does not work well: it is mainly because loose bolts of the governor mechanism are loosened. The governor pole and the hole are too loose; the fit between the governor pole fork groove and the adjusting arm ball head is too loose; the gap between the governor sliding plate thrust bearing and the speed governor lever is too large; the governor gear end face is in contact with the steel ball; There are pits and other causes. (2) Failure of the fuel system: Mainly there is air in the low pressure oil circuit; poor sealing or wear of the oil valve; abnormal operation of the fuel injector; and inflexible operation of the oil pump plunger. Remedy: If it is due to the cause of governor work is not working, start by checking the governor mechanism: (1) tighten the tightening bolts of the governor mechanism; (2) align the relevant parts with the clearance; (3) If the parts are worn, the S195 diesel engine can add about 1 mm of gasket between the one-way thrust bearing and the speed governor. If it is caused by a malfunction of the fuel system: (1) Exclude the air in the fuel system; (2) Grind the oil or replace the outlet valve pair or the plunger pair; (3) Adjust the injector or replace the needle valve pair.