Tech Tip 8 Using Treated Fuel in your ATV

 If you happen to live on a farm that regularly utilizes the services of an old gas powered tractor you know all about having to “treat” todays unleaded gas with one of the many synthetic lead compounds that are available for premixing. This synthetic lead lubricates the valve seats and will keep an old gas engine that originally required lead running. Some farms will have a bulk quantity delivered either already treated or it is treated as it is pumped into the storage tank on site.

 This fuel is tempting to use for your ATV’s motor too. However don’t do it! In a modern engine that doesn’t require either leaded fuel or the treated variety, there is a carbon build up {Carbon1]. So? Carbon buildup is a “normal” part of combustion, right? Sure is. HOWEVER, Check out the closeup [Carbon2] notice the thick build up on the piston’s crown. See how the valve pocket is almost completely filled up. So? Finally note the white sections of the carbon. All of this carbon was caused by the synthetic lead and unlike normal carbon, this stuff is brittle and flakes off readily. In fact, the white pieces are ready to flake off at the slightest touch. The pieces get caught under the exhaust valve and hold it open slightly reducing compression. They also can “whisker” a sparkplug. A whiskered sparkplug has a piece of carbon bridging the gap of the plugs electrode, shorting it out.

How long did it take to accumulate this much carbon? Three summers. How do you get ride of it? Remove the head and scrape it off! The moral: Use only unleaded fuel in your ATV even if that “treated” fuel is handy.