I have an older 420 that has become hard to start. Once I'm able to get it started and it warms up a little it runs ok, maybe a little weak, but ok. When I try starting it, it spits fuel out of the carb, like the accelerator pump is kicking in when it doesn't need to.
Maybe an intake valve sticking? How would I check or what symptoms would confirm? The fact that it clears up somewhat once it warms up kinda throws me.