That diaphragm being hard is a tip off to the alcohol in the new fuels. It destroys the elastomer qualities of the rubber and they fail to flex as they should, rendering them inefficient or inoperable.
The piece of grass is revelatory too. Wonder how it got past your air filter? It might have been introduced by a field attempt of a repair. You can't guarantee cleanliness in those conditions.
Good to hear you got it all figured out...
Maybe it's time to run an expose on alcohol in fuel and the dire consequences of it. If left in contact with rubber or flexible plastic parts, things can get brittle and fracture or fail to flex as needed.
Use good gasoline...stay away from brands with the first letter of "A", "B" "M" or "T" as a rule try to get some Chevron...but use the lowest octane you can get. 87 Octane R+M/2 is correct for your engine.
R+M/2 = Research octane plus Method octane divided by 2. |