It starts fine when hot though, using the hot-start button. I'm using the prescribed technique from manual (accept I give it maybe 6 - 8 primes instead of 5), the method that worked fine for the first 5 years of my YZ's life. My accelerator pump is working fine, jetting hasn't changed since it's been starting good cold. My valves are on the tight side but they're still within tolerance. Could this cause hard starting when cold but not when hot???