I have a Lincoln welder with a 16 hp briggs Stratton engine that will only run with the choke closed. what could cause this?

  • Welcome to Motor Vehicle Maintenance & Repair! Have you done any troubleshooting on it yet? Is this a new or used system? I would guess (off-hand) that there may be some clog or air leakage (like from a cracked hose) in the carb. Have you checked the carb out at all? Commented Mar 26, 2018 at 16:51
  • It is an older machine I think 1970"s I replaced carb gasket which I believe was causing overheating after about 10 mins of welding ran good for a while I have looked other leaks sometimes easy to miss.
    – j r
    Commented Mar 28, 2018 at 14:11
  • The main jet is partially clogged, time to disassemble the carb and clean out all the fuel passages. there is no such thing as a mechanic in a can, you just have to do as suggested.
    – Moab
    Commented Apr 4, 2018 at 22:30

1 Answer 1


This is most likely an issue with the carb having issues with ethanol clogging. You may be able to get it work by using something like SeaFoam thrown into the gas tank at a high concentrate. This may entail rebuilding the carb, but I've found it's usually worth my money to replace the carburetor directly due to the amount of time/effort it takes to get a rebuilt carb running correctly.

What is going on is the ports in the carb have become gunked up due to the ethanol. The reason it will run with the choke on is because there is a greater amount of vacuum draw on the ports, which gives the engine the gas it needs to run. Unfortunately, it usually runs too rich and doesn't run as fast as it should, which causes other issues (low generator output).

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