The manual states that it needs 50:1. Many suggest that you use a slightly fatter oil mix of, say, 40:1 to extend the engine life.
The fuel mixture screws on the carburetor are often set a bit too lean also, which will cause piston burning and siezure if not immediately addressed. If the engine seems to run out of power after a minute or so of hard cutting, the fuel mixture screws likely need to be richened slightly. Of course this takes a special tool or a trip to your service shop, but it's definietly worth it for the extra performance and more so for the extended life.
Hope this helps!
dr bob, May 2008
