How do the 2cyl-4 Stroke 25hp Yamaha (136lb)<br />and the 3cyl-4 stroke 25hp Nissan/Tohatsu(151lb)<br />compare for a Sea Nymph 14R...Or would the 18hp<br />Nissan/Tohatsu(115lb) be enough motor? Service is available for both makes. We usually have 500# of people plus typical fresh water tackle<br />on board.