Need a little help on my riding mower. Just rebuilt the carb. New gas. Engine starts up fine, runs for about a minute and then dies. It will start back up and then quickly dies again. I noticed the plug was an autolite. I will change it out to RC12YC tonight. Any ideas? Could it be the plug? The carb has an adjustment on it but not sure if this is the problem. I was thinking maybe the fuel solenoid may be not working but I checked and it appears to open and close. Any help would be appreciated.