Check the choke: If your Samurai is only running well with the choke open, it could be a problem with the choke itself. Make sure the choke is properly adjusted and operating smoothly.
Check the air filter: A clogged air filter can restrict airflow and cause a rich fuel mixture, which can lead to black smoke and idle issues. Replace the air filter if necessary.
Check the spark plugs: Worn-out or fouled spark plugs can cause a misfire, which can lead to black smoke and idle issues. Check the spark plugs and replace them if necessary.
Check the ignition timing: If the ignition timing is off, it can cause a misfire, which can lead to black smoke and idle issues. Check the ignition timing and adjust it if necessary.
Check the fuel pressure: Low fuel pressure can cause a lean fuel mixture, which can lead to black smoke and idle issues. Check the fuel pressure and make sure it is within the recommended range.
