My yd25 engine starts hard when its cold what causes that

Oil can cause it or it could be the battery. Normally in cold weather you want a thicker viscosity like a 10w-40 and in the summer you want a thinner viscosity like a 5w-30

You can change the oil so its a little thicker if its that cold in your area. I don't know were you live but if your reaching the cold weather like in the 30s in the morning then changing the oil to a thicker oil could help.

Or a cheaper first try is to test that battery you have its cold cranking amps could be failing on you. So this is what you want to do;

If you got a battery jump starter you could try that in the cold morning and test it that way and see if it starts if it does then its the battery.



Hope that helps if it don't let me know. Oil can cause it or it could be the battery. Normally in cold weather you want a thicker viscosity like a 10w-40 and in the summer you want a thinner viscosity like a 5w-30
You can change the oil so its a little thicker if its that cold in your area. I don't know were you live but if your reaching the cold weather like in the 30s in the morning then changing the oil to a thicker oil could help.
Or a cheaper first try is to test that battery you have its cold cranking amps could be failing on you. So this is what you want to do;
If you got a battery jump starter you could try that in the cold morning and test it that way and see if it starts if it does then its the battery.

Hope that helps if it don't let me know.