I went to fire it up today, and it was only hitting on the left side. I took the left plug out and put it on the right side and it started running on the right side, but nothing on the left. I then found a spare plug, and put it on the right cylinder, and put the plug I knew was good on the left cylinder. It still only fires on the right cylinder now. Now I can't get anything out of the left cylinder, no matter what plug I use. What is going on here. I'm baffled?????