Where do I start? Sorry if this is a bit long-winded. For years our bus ( '76 2L ) started brilliantly, regardless of the conditions. But we've had a series of sagas and this is the latest one. For a while now starting has been a bit "iffy". Sometimes it would burst into life, other times it would take quite a bit of cranking, even warm, sometimes the starter would bog down initially (as if the battery was flat) and then recover. It always did start eventually, but the problem seemed to be getting worse. Last weekend we had to go to something in the highlands. It was a cool morning and we just couldn't get the bus started. Afraid I may have flooded it I cranked the starter with throttle open but it showed no sign of firing. Eventually, I flattened the battery. I thought I'd jump start from the "domestic" battery (it's worked in the past) but, surprisingly, that would barely turn the engine over. We jump started from a neighbour's car and it started instantly. Thinking our battery may be on it's way out (it went flat rather quickly) we bought a new one on the way. When we stopped for lunch I installed it. The engine turned over beautifully but refused to fire. However, it bump-started immediately. The morning we were to return was cold and very damp and I flattened the battery trying to start the bus. We tried jump starting from a 4WD with heavy cables and it still showed no sign of firing. For some reason it would still only turn over very sluggishly. However, when we tried tow-starting it fired up without any trouble. On the 6 hour trip home I accidentally switched the motor off once and it re-started immediately. But on two occasions we stopped facing downhill and had to resort to bump-starting to get going again. Both times it fired up instantly. Once going it seemed to run normally. The next morning it wouldn't start first thing in the morning, but did start, with some effort later in the day. This morning (cool but not cold, and not damp) I flattened the battery again. Anybody got any idea what's going on? A couple of things I've found on my own, that may or may not have some bearing on this: I suspect the device that isolates the domestic battery from the starting battery may not isolate particularly well. I never had a lot of confidence in it. Perhaps I have been flattening both batteries at the same time and that's why I can't jump start from the domestic battery. I've disconnected the domestic battery for the moment. I noticed that, when stone cold, the RH choke butterfly was still half open whereas the LH one was shut. I took the choke off and tried closing the butterfly manually but I can't. It stops halfway. It just wont go any further and if I try it sticks and wont spring back. Any idea what the problem may be? I realise this would have affected the starting but does it explain why it wont start with the starter but starts easily otherwise?