The town wharf on Kingston Bay has been closed for repair and preservation work, a project that will keep boats off the wharf’s slips and moorings this fall. The wharf, which provides boaters access to the bay, has suffered in recent years from rough weather and heavy demand. Town Meeting approved spending Community Preservation Act funds on the project, which was expected to begin construction before the summer boating season. But town officials said the engineering work for the restoration took longer than expected, and the town decided to delay the work until after summer. The Waterfront Committee said the project is expected to be finished by late December.