if you are on a tight budget and want to get an engine that is reliable and will last a while for your $300, any novarossi based engine is good for you. the max is a very good engine. the new mega (made by pico) is a very fast engine, and the upfront cost is also good (about $260 for engine and pipe). but it will cost more to run this engine. you have to change the conrod about every gallon ($30 a conrod). the conrods to break and they can also cause internal damage to the engine, which will ruin it. also, they are having air leak issues. until they get these issues resolved, i woul go with the novarossi engine.