"Governor might have been a better job for him to have started with," Romney joked.
The stop was the first of three planned appearances in small towns in this state with 20 electoral votes that Obama won in 2008 with 54 percent. No Republican presidential nominee has carried the state since 1988.
Romney appeared with former Minnesota Gov. Tim Pawlenty, a possible running mate, who told the crowd, "Mitt Romney's message is: It will be better."
The tour is intended to challenge Obama in states where he's strong. Romney is targeting smaller cities and towns through the state's more conservative midsection. Weatherly is in Carbon County, which Obama narrowly carried in 2008.
Romney also was scheduled to stop in Quakertown, in Bucks County, as well as at Cornwall Iron Furnace, a national historic landmark. That's in Lebanon County, which GOP nominee John McCain won in 2008.
Romney's is on a bus tour, but he planned to fly each night to the next state and ride from town to town during the day. It's his first traditional campaign swing since the primary and is aimed at undecided voters in six pivotal states won by Obama four years ago: New Hampshire, Pennsylvania, Ohio, Wisconsin, Michigan and Iowa.
The tour represents a new mode for Romney in the general election. During the primary, Romney sometimes ran into trouble in less-scripted environments and the bus tour probably will test him again. He also has long faced questions about his ability to connect with average people.
The last time Romney was in Pennsylvania, he campaigned with Sen. Marco Rubio, R-Fla., and said he was "studying" the Cuban-American's ideas for legislation that would allow some illegal immigrants to stay in the country to work.
The opening of Romney's six-state, five-day tour was overshadowed by Obama's announcement Friday that the U.S. no longer would deport some young illegal immigrants who came to the U.S. as children. In response, Romney softened the harsh rhetoric he used in addressing illegal immigration during the contentious GOP primary campaign.
"It's an important matter to be considered and should be solved on a long-term basis so they know what their future would be in this country," Romney told reporters after stepping off his bus in New Hampshire. Obama's executive order was problematic, he said, because "an executive order, of course, is a short-term matter. It can be reversed by subsequent presidents."
That measured response echoed Rubio's own reaction to Obama's announcement. Although pressed by reporters, Romney refused to take a firm position or say whether he would, if elected president, reverse the executive order.
The focus on immigration also threatened to raise questions about whether Romney would shift his positions based on changing political circumstances.
Romney, a former Massachusetts governor, adopted a tough line on immigration during the primary, calling the main immigration bill in Congress a "handout" and saying he would veto it as president. The legislation would provide a pathway to citizenship for young illegal immigrants who attended college or served in the military.
Romney faces pressure to appeal to the Hispanic voters who will be critical in Nevada, Colorado and elsewhere, but he also risks alienating his conservative base if he abandons his previously tough stances.