Well since your are saying its sputtering & backfiring, below are some list of items you may want to check.
* Check to see if you are using the right fuel type in your car, using low octane fuel in a car requiring high octane will cause premature detonation similar to back-firing
* Check your timing and if any of the spark plug wires are crossed if any one worked on the ignition system lately The above items are pretty easy to check.
Sputtering will also occur if any one your cylinders are not firing. Usually occurs when you first take off and in overdrive. But once you are up to speed it does not happen anymore.
By adding a fuel additive in the gas tank you are going to get better gas mileage. It cleans all the injectors and all the fuel lines and the rest of the system.
water in the fuel system may need tune up try some dry gas additive
Most likely a clogged fuel filter. If the vehicle has been out of use for a long time, it may also be due to contaminated fuel. Adding a fuel system cleaner or fuel additive such as heet, in addition to a quantity of good fuel should alleviate the problem if this is the case.
Weak fuel pump Bad fuel filter
There is no fuel additive that will increase mileage. This is a myth. None of the snake oil additives work.
If its clogged
no
Bad fuel,clogged fuel filter,fouled plugs.
depends...does it have a carburetor or fuel injected..?
The engine backfiring at idle, and at slightly off idle speeds is indicative of a lean fuel/air mixture. Try enriching your fuel mixture.
To stop a Yamaha 1300 from backfiring, first ensure that the air-fuel mixture is balanced, as a lean mixture can cause backfiring. Check and adjust the carburetor or fuel injection settings, if applicable. Additionally, inspect the exhaust system for leaks and ensure that the spark plugs are clean and functioning properly. Regular maintenance and tuning can also help prevent backfiring issues.
Two independent studies rated Opti-Lube XPD as the best diesel fuel additive.