The signs point to a leaking head gasket. I’m just not sure why a new head gasket would be doing that. It was recently installed, 7.7 hours ago to be exact, with my new Cylinder Works big bore kit. I’ll describe the problem in hopes that some one can point out something I’ve missed, either a different problem, or why the head gasket might be leaking. Bike is a 2005 S ModelCW Big Bore kit w/ single layer base gasketHot Cams, not new to the bikeE model FCR, not new to the bike Stock pilot, adjustable fuel screw, James Dean needle on 4th clip, 170 mainYoshimura Ti exhaust, not new to the bike eitherK&N air filter, 3x3, all the standard stuffEngine Ice in the cooling system I took my bike to my friend’s shop for the big bore install. Bike was running just fine, but I wanted the extra power. My spare time is limited and he gives me a break on parts/labor. So why not? Install seemed to be fine and the bike ran great. I installed an hour meter and after 2.6 hours of easy break in, I changed out the break in oil and filter. After the oil change I took it out for a 1.5-2 hour ride to see what the bike could do. Ran great, with seemingly no issues. When I got home and put the bike away I noticed the coolant reservoir was nearly full. The next day I drained it and topped off the radiator. I dismissed it as a fluke. Next day, I ride it to work. It was an easy commute in 45-degree temps. We can split lanes here in California, so I was always moving. I get to work and look down; the coolant tank is half full again. At lunch I decided to take it to my friend’s shop. It’s within walking distance. His mechanic gave it a visual and suggested I try a new cap. They gave me a loaner to try. It doesn’t say, but I believe it’s a 1.3 bar and it’s from CV4. When I pop off my stock cap it pukes warm pressurized coolant. Not too odd considering I rode it over there. The ride home seems fine. No additional coolant in the reservoir when I park it. Problem solved, so I thought. Two days later I pop off the cap to check the fluid levels, and it pukes cold pressurized coolant out. Now I’m bothered. The cap was just a band-aid for something else. My friend with a GSX-R says his radiator stays pressurized and not to worry too much about it. But a head gasket leak was looming in the back of my mind. I researched possible causes and decide the mechanic probably torqued the head to 34 lb ft. That weekend I decide to retorque my head to the TT suggested 43 lb ft. I loosened the head bolts (possibly a mistake, but what did I have to lose?) so that I could retorque them starting at 18, 34, then 43 lb ft in the recommended pattern. I also adjusted my valve clearances; they were in spec but right on the tight limit since install of the Hot Cams. I also raised my needle one notch, to the 4th clip because it seemed a little lean and a richer mixture would run cooler. I ride it to work again, no additional coolant in the reservoir. Ride it home and once again no coolant in the reservoir. Two days later I pop off the cap to check coolant levels. Good news, no big pressure release and coolant spill. Bad news, the coolant level is low. I think to myself “Darn. Only one other place for it to go, into the engine.” I don’t see any external coolant leaks, I don’t have white smoke coming out of the exhaust, the bike doesn’t seem hot. There isn’t any sign of coolant in the oil (on dipstick), or oil in the coolant. It really has me bothered. I don’t believe the mechanic used the copper spray on the head gasket. So that’s a possibility for the leak. So is a defective gasket, a cracked/warped head, or a defective cylinder. But could it be other cooling related issues instead? Water pump or thermostat failing? Huge pocket of air in the system? I just want to try to cover my bases before pulling the head and replacing the gasket. Sorry for the novel. I appreciate your help. Thanks!