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.
If so, you want to get the pre-emergent down specifically before the crabgrass germinates. In your area, that should be awhile, (written in February) but the only way to tell is by soil temperature. When soil temps get up to about 55 degrees for 1-2 days, the crabgrass will start to germinate.he temps in the evenings is right at 60. ANSWER: A Pre Emergent weed killer can be an important weapon in your arsenal to fight weeds, especially the persistent problem of crabgrass. However, your question points out how important it is to get the right tool for the right job.