Joe, the pump OS is using has been used for years and years. It replaced the first one they used that was a metal unit, I have a 1.20 with one of those too. The pump is not anything that can be fixed by the owner. {sorta} If they gunk up with castor the owner can clean them and get them going again. It's a replacement part. There isn't anything in there to really mess up so the pumps don't go out very often. The big tic me off is the regulator!! There is really nothing in there either but there is a diaphram, a cheap little black item that any four year old could replace!! You can buy a new regulator cover from OS but they will not sell you a new diaphram. They want you to send them in the complete carb so they can check it out and replace that 50 cent part OR replace the complete carb with regulator!!! I need a new diaphram in one of mine!! Because of this and the new and improved price of the OS and Saito engines I question why anyone would buy anything other then a YS?? However, I get a few guys that feel they need to pay me for my help/work and I get a few OS four strokes given to me. I love the OS engines and will take all that I can get! The .91 is on the top of my list, wish someone would give me one of the older 70s, I sold the last one I had and that was another one I like as much as the .91. There, I vented!! Anyone have a diaphram for a OS 1.20 they don't need???