Original Zenith 28 and 228 carburetors came with a metal accelerator pump. A cheap kit does not come with an accelerator pump. They usually don't wear our and you have 3 grooves to put the cotter pin in. If you want the shooter to squirt a little more, you give it more stroke. A lot of after market kits, that do come with an accelerator pump, come with a rubber or leather one. It looks like you have an aftermarket pump that couldn't stand up to E10. You need to get a kit that comes with an accelerator pump. I prefer the metal ones.