When using the single-vacuum distributor, the vacuum hose runs from the vacuum port on the left side of the carburetor to the vacuum canister on the distributor. In that case, the vacuum port on the rear of the carburetor must be plugged.
For most cool season grasses and for folks living in northern climates, the best time to plant grass is in late August, early September. Depending on exactly the climate you have and the type of grass seed you're planting.
Overview. Fall is usually the accepted time to plant grass seed so you will have a lush, green lawn by the time the weather warms up. April is the next best time. Seeding in spring must be done early so the grass has a chance to become established before summer heat sets in, but can't be done so early that the seeds will rot in the freezing and wet soil and to prevent weeds from overtaking the fresh seed.