Normally cars only have 1 belt called a serpentine belt.Some cars have a timing belt that should be changed when the manufacturer recommends(60,000-75,000 miles)Consult the owners manual or contact a dealer or most automotive supply shops.

The best fuel ratio for any engine is around 14 to 1.Do you mean the oil mixture ratio?You should look on the engine itself.You may have to left the cover to find this or get the model number and find a marine shop.They should be able to tell you.