Speaking from a dealer's point of view. Warranty only covers manufacturing defects in the material and craftsmanship of the product regardless who manufactured the product. Power equipment manufacturers and power equipment dealers have absolutely no control over the manufacturing of fuel. We have no control over fuel stations increasing the gasoline/ethanol mix ratio to make a few extra pennies either. I haven't seen any Dolmar, Stihl, Husqvarna/Jonsered gas stations around. Have you? We have no control over Joe Homeowners 30 year old rusty gas can he decides to mix his fuel in either. We have absolutely no control over what the EPA decides to force/mandate. The EPA mandates every piece of power equipment to be screaming lean, creating excessive heat and rpm issues.
A dealer must always error on the side of caution everytime someone comes in with warranty issues. Most of the time they are looking to get something for nothing. They are not afraid to lie/cheat to the dealers face to get it. Manufacturers, dealers, and their employees are not stupid. If a warranty claim get rejected by the manufacturer, guess what? The dealer gets to pay for it out of his pocket. That mean's less money make payroll, less money to pay bills/insurance/taxes, and less money to take care of his family. Yep, dealership owner's and their employees have families to support too. Dealerships can also be investigated, hauled to court, and fined if the manufacturer suspects you're passing frivolous warranty claims. So THINK before you whine and cry to your dealer over a rejected warranty.
I just finished repairing 3 month old Dolmar PS-5100 S w/a leaky intake boot, scored piston and cylinder. The customer was also running mix fuel out of his pontoon boat from last summer. So a combination of an air leak, excessive rpm, excessive heat, and rancid improperly mixed fuel destroyed his saw. We were able to warranty the leaky intake boot and some of the labor.
Old fuel burns at a much higher temperature. Old fuel also burns very inefficiently, causing starting trouble, idle trouble, power trouble, excessive carbon build up, and can ultimately destroy your equipment. Manufacturer's and dealer's will automatically reject a warranty if old fuel is suspected. If your fuel is older than about 3-4 weeks it's junk. Plain and simple. Mark your fuel cans with a purchase date and a 3-4 week expiration date. Always use a quality name brand mix oil. Remember, your air cooled saw engine runs 2-3 times the rpm your liquid cooled car/truck does at full throttle. Saw engines operate at much higher temperatures than you car/truck does. Fresh fuel, quality mix oil, proper carb adjustments, and air flow are all that keep your saw from burning up.
Nick
You really believe that fuel is junk after 3-4 weeks?
Bull crap.