I know this is slightly off topic as the engine's in a mower but I recently bought an ex demo Bolens lawn tractor. It looked imaculate, I suspect it had never cut any grass. Anyway, it came off eBay for about1/2 price and worked well so I was happy. It has a 13HP Techumse engine and replaced an old Sears mower with a B&S that worked well for many years until the back axle snapped. Anyway, the new one was put to work and all was wonderful. Then it began hunting slightly and its 13 horses seemed a little lame. Over the next few running hours things got worse until it would only run on full choke. Cleaning the carb and plug only seemed to make matters worse until it ran no more. Further cleaning of the carb changed nothing. The engine would only start with my hand covering most of the carb mouth or with petrol dripping from a brush into said carb mouth. By now I'd had the carb in bits more times than I can remember and grudgingly admitted defeat by taking it to my local mower company, muttering unprintables as I did so. When I bought the mower, it came without any paperwork except a rather nondescript receipt. Fortunately that was enough to prove it's date of purchase so it should be under guarantee. The agent says it needs a new carb. I suppose at =A365/hr, it's cheaper than paying them to fiddle with it. Techumse are considering the warrantee claim but the good news is a new carb is only about =A335. I assume there's VAT on that but it's still less than I expected. As a comparison, my smaller mower needed some drive belts. For some reason, MTD seem to have them made to their own spec. They cost =A330 each! Now I've got the part Nos, I can get them of the 'net for about 1/3rd that. In the meantime, the grass is loving this weather and is growing like crazy. Does anyone rent out horses or sheep?