Carburetor numbers: 4955S, 4956S, 6025S, 6026S
Rough idle due to over rich condition on the subject units. Should such condition occur install a plug as show in the illustration. The plug should be driven to mating surface only.
Smooths out when adding a bit of gas to the carburetor throat. Ideas are not in any order.
- Weak fuel pump pressure. Test with a fuel pump tester. Check your manual for the exact measurement but should be around 4.5 lbs.
- Dirty fuel filter. Change the fuel filter every 6 months.
- Look for kinked or damaged fuel line that might be restricting fuel.
- Do you smell varnish? This happens when the engine has been sitting for months. Gas turns and varnishes the inside of the carburetor plugging the small passages. When cleaning you need to blow air through each passage while looking to make sure the air comes out the other end of the passage. Keep in mind that when this happens the gas tank and fuel lines will need to be removed and cleaned, otherwise you will have the same problem over and over.
- Float level is off keeping the gas level too low.
CARB WON’T IDLE
If just can’t get the carb to idle down hot, or cold, top of the list is the throttle valves. They may have been inserted in the wrong direction.
It doesn’t take much of a bump to nick the throttle valves or knock them out of alignment. If this happens, it will be impossible to get the two sides of the carburetor balanced or the engine idle smoothed out.
