Once you learn the many great attributes of Super Tigres carbs, you won't slam them so hard. They can be adjusted three ways, not just two, so can be really tuned. The ST .51 is a punched out .45 and makes good power, for next to no money. You need to make sure the throttle retainer screw is tight. I usually put on blue locktite on mine from new and never have a problem. The fuel inlet nipple can be rotated slightly to sweeten the midrange. Almost all of mine work great when the nipple points to the rear engine mounting screw hole. This is a ringed engine, so lasts much longer than ABL or nickel plated non-ringed engines whene the thin plating wears off or fails.

I really love my OS's, but they are NOT the only good engine out there. Other good options not mentioned for this airplane are the .52 Magnum and the .46 Magnum. They both equal the power of their OS counterparts. All three of these engines require break-in. Follow the engine manual and you can't go wrong.

What one gent mentioned is very true of the lighter, trainer engines. You usually end up putting the battery pack under the tank and have to put a Higeby Heavy Hub on the front end to balance the plane with the light LA motor. The LA has an air bleed carb, instead of a twin needle and can get finicky in hot weather like our expert from Japan has never experienced (over 100 here in Texas). The .50 sized engines can be run richer and still put out enough power under hot conditions to enjoy flying your trainer. Also, you can transfer the hot .46 or .50 something to a nice second airplane and have the power you need for the next level, without buying another engine.

Have a safe and enjoyable Labor Day Weekend!!