Carles,
Welcome to the WFM forum! A P220 in the 318 is a very good re-power. The additional spring is not right the way to solve the underlying symptom of proper idle and governor function. the TM1590 covers the 318 and the 420 tractors, so it has information on the P220 engine as well as the P218. You can get this manual on CD or in hard copy from your Deere dealer or online at
http://techpubs.deere.com/deere/Default.aspx
Section 220-10 has some good information on how the governor should be set.
Note that the manual indicates that the low idle is specified at 1350 RPM which may seem high to some...
I will send you some other information as well, it is a bit too large to attach here.
Chuck
Welcome to the WFM forum! A P220 in the 318 is a very good re-power. The additional spring is not right the way to solve the underlying symptom of proper idle and governor function. the TM1590 covers the 318 and the 420 tractors, so it has information on the P220 engine as well as the P218. You can get this manual on CD or in hard copy from your Deere dealer or online at
http://techpubs.deere.com/deere/Default.aspx
Section 220-10 has some good information on how the governor should be set.
Note that the manual indicates that the low idle is specified at 1350 RPM which may seem high to some...

I will send you some other information as well, it is a bit too large to attach here.
Chuck