SPIRIT LAKE - The high-powered, souped-up lawnmowers at the 11th annual Big Back-In won't be trimming anybody's front yard this summer.

Revving and rumbling through downtown Spirit Lake, the mighty machines were all business on Sunday afternoon. As daredevil drag racers pushed their steeds toward maximum velocity, the mowers charged down Maine Street, popping wheelies and burning rubber.

"It's just hillbilly fun," said Mike Lines of Rathdrum, watching the mowers peel away from the starting line. His stepson, Zach Hood, was among the competitors.

"Last year he went 17 miles per hour," Lines recalled. "This year I think he already hit 30, or 31."

Forty-two riders took part in this year's Back-In, a longstanding Father's Day tradition. They competed in three racing classes: stock, modified and super modified.

James Rees of Athol rode a gray Sears mower that was anything but stock (and carried no cutting blades, of course).

The 19-year-old had swapped the motor, changed the rear end and pulled out the governor. It may have been rusty and a little beat up, but the old mower could hit 30 mph on a long straightaway.

"It's a wheelying son-of-a-gun, and it seems like if I give it full throttle it wants to tip over backward on me," Rees said.

He's been a regular at lawnmower races for about five years.

"I've been racing since I was 14, flat track and drag. It's a blast. Lawnmower racing is a blast."

A few of the contraptions were just plain wacky. Mark Kroetch piloted the "Mowertician," a finely-built machine that looked like a wooden hearse. Equally macabre was Brad Strength's long, black mower shaped like a coffin.

Chris Henderson of Rathdrum sat astride the "Mowzart," a bright yellow-green specimen that he's taken to 29 mph. Inspired by Kroetch, his father-in-law, the 30-year-old Henderson took up lawnmower racing three years ago.

Driving his burly Sears racer, he said, isn't too difficult. The ride is usually nice and smooth.

"It's not bad. It's pretty laid-back, simple fun," Henderson said. "And it's cheap."

Several hundred spectators, many enjoying a burger or a beverage, lined the makeshift drag strip. They cheered on their favorite racers rattling down the road.

The Back-In raised funds for recreational projects in the Spirit Lake area.

"It started in my dad's bar, the Linger Longer, so I've watched it progress," said Barbi Reisenauer of Spirit Lake. "It's a great event for this little community. It's great for the businesses in town."

Racers young and old, male and female strapped on a helmet and hit the roughly 100-yard drag strip. Aboard a custom 14.5-horsepower mower, 19-year-old Kymberly Bowlby of Spirit Lake competed in the super modified class.

About 2 p.m., she had yet to suffer any mechanical mishaps - a common occurrence at the Back-In.

"I've never won Spirit Lake, 'cuz I usually blow up something," Bowlby said. "I like the adrenaline rush. Usually by this time I'm shaking."

On a flat course, Bowlby can push her mower to 43 mph - a bit faster than your grandpa's John Deere. But that kind of pace is unlikely at the Back-In.

"Here in Spirit Lake you kind of have an uphill (track)," Bowlby explained, so racers usually won't hit their top speeds.

Still, a digital sign at the upper end of the track - normally employed as a deterrent to speeding - registered 15, 20, 30 mph or higher on Sunday.

Swift and loud, leaving a trail of dust behind them, the mowers blazed toward the finish line.

"It's a big redneck event," Reisenauer said with a laugh.