fwiw, my tt39 ran great...but i pulled it, and now use an os37szh...runs much better, although it's a little thirstier for fuel...btw, i use all-synthetic, so it's hard to see if there are any leaks...you might have to drop the engine and take it apart to see if you have a pinched gasket or loose bolts...to get started, just get your 3mm driver, and pop off the throttle linkage....ken