Roger,

The reason older MB engines start harder than your JD tractor is probably because the MB is pre-chamber injection and the JD is direct injection. Direct injection engines are known to start easier.

I have a 40 year Case tractor with direct injectionand it starts easily without using the manifold heaters down to about 45*F.

Why MB chose to use pre-chamber injection instead of direct injection, I do not know. Maybe someone else can answer that question.

The newer MB are now direct injection.

P E H