So a few months ago I was having coolant issues - after a long fast ride, if you stopped the engine, coolant would come firing out of the reservoir bottle and shoot a foot and a half in the air. Spectacular but embarrassing in public. I found I could control this by refilling the radiator while tilting the bike on extreme angles, which would release quite a decent amount of air bubbles. The bike would then run without shooting coolant for a certain amount of time, and then it would start again. Aha, I thought, there's a small air leak somewhere. So I plonked a thing of radiator stop-leak in the bike a couple months ago, and that stopped it altogether until last night, when I turned off the bike in the driveway. A few seconds later the radiator shat itself, and coolant and steam pissed straight out of the back of it somewhere. The bike hadn't been running at high temp, I'd just come down the freeway on a cool evening. I'm running through the possibilities in my head here, help me out: 1 - stop leak solution decided to stop the leak that was the outlet to the reservoir bottle, and the resulting pressure blew the main radiator up 2 - radiator cap thermostat gave out (an easy test to do anyway) 3 - there's still an air leak somewhere 4 - the head gasket has gone, and the bike is pumping exhaust gas into the coolant 5 - I've suffered "wheelie damage" not dissimilar to what happened to Cheffie Right now I'm imagining a combination of 1 and 4, and not liking the implications. How hard is it to put on a new head gasket? :grin: Any ideas?