Hmmmm. Fill my car's gas tank or buy a new lawn mower? Tough decision, but according to small-engine manufacturer Briggs & Stratton (NYSE:BGG), that's what consumers are apparently asking themselves these days. Because of this, the company is preannouncing that fourth-quarter net sales in its important engine segment will be 18% lower than originally predicted.

Companies are blaming high energy prices for shortfalls on everything. Whatever the bugaboo of the moment -- high oil prices, hurricanes, sunspots -- you can be sure some managers will use it to explain away faltering performance, regardless of how tangentially related the event is.

Earlier this year, Briggs & Stratton explained that slowing sales were the result of a late start to the spring season. Feeling the season was over, retailers like Home Depot (NYSE:HD) and Wal-Mart (NYSE:WMT) were withholding their purchase of mowers and other backyard power tools. While that's still part of the reason why the company's earnings will only be $1.94 to $1.99 per share -- 246% lower than previously forecast -- the company said the problem was compounded by high oil prices, rising interest rates, and retailer inventory management programs. Whew! A regular cacophony of catastrophes conspiring to keep the engine maker down.

While the company is struggling to stem the tide of falling sales, it must also deal with a mass exodus of workers who are taking advantage of guaranteed benefits under an expiring labor contract. The contract, which expires Aug. 1, gives retirees with enough seniority free health insurance for 10 years. As many as 260 workers are leaving one Milwaukee-based factory, about one-third of the workforce there. Briggs & Stratton employs some 9,000 people companywide.

The engine segment comprises two-thirds of the lawn and garden equipment manufacturer's revenues, down from more than 85% just two years ago. Part of the reason for the decline is that Briggs & Stratton acquired the assets of defunct Murray, a move that primarily boosted revenues in the power equipment segment; however, sales there are also expected to come in 18% below company forecasts. The engine maker will report full-year results on Aug. 10, but thought it would get the bad news out early. Investors, though, punished the stock, driving it down 16% in after-hours trading, though it opened trading today only 7% off.

While the macroeconomic trends the company singles out may indeed be the culprit in declining sales -- after all, Briggs & Stratton notes industry forecasts for engine shipments to manufacturers will be off 7% to 8% for 2006 -- we've been living with high oil prices for quite a while now, and the first six months of Briggs & Stratton's fiscal year saw sales growing briskly.

With competitors like Honda and Tecumseh (NASDAQ:TECUA) seeing improved sales (though the latter is still recording earnings losses), Briggs & Stratton looks like a company in need of a jump-start.

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Fool contributor Rich Duprey owns shares of Wal-Mart but does not own any of the other stocks mentioned in this article. You can see his holdings here. The Motley Fool has a disclosure policy.