The WS series of engines have always been my favorites!!! They are a square stroke engine with a smooth bottom end and tons of top end!!! Best part was they are a very easy engine to tune. One thing you will want to remember is the engine does not have a really aggressive bottom end. I used to run a 50 tooth spur on my Losi rather than a 48, so I could get a little extra grunt. Around here we have tracks with short run ups to jumps so I would change gearing or run heavier clutch springs. If you have an open flowing track this engine will be great with your normal gearing/cluth. If your track is tight and requires a lot of torque you may need to play with gearing and clutch.

Also they say to replace the rods at 3 gallons but I have never done that. I had several WS7 engines make it well over 10 gallons on the stock rod and bearings. Pre heat the engine and keep dirt out of it and it will last a long time as is!!