Bought it for 150 dollars, Motor ran good for about a week in a drum waiting to get the boat registered. well guess what got the boat registered and in the river won't start. back home in the drum ran good, back to the river won't start. now it won't start in the drum. step son messed with carb. says he didn't but I no he did. well check the kill switch, pulled it off put different switch in still don't start. check the carb. clean real clean. how to adjust the carb air/fuil mixture. how to check the coils for fire. any suggestions. 