I had a new (not OEM) head installed on my L4630 (2300 hours) a few weeks ago. The old one was cracked and leaking coolant. Since the new head install the tractor seems to be going through fuel much faster. I keep the tractor in my shop building and when I start it and pull it out it leaves such a cloud of blue in the shop that I have to leave the door open for quite awhile before I can go in and do anything. Is there any reason for this that you know of? It seems to me that a new head would result in better operation (less fuel, less exhaust) nor more. I appreciate any ideas you might have about this. Thanks.