I have a Troy-Bilt Mower - Model 834. It has a Honda GVC 160cc engine. It is supposed to start after two pulls when cold and did so since I bought it in 2006. But, just recently it takes 6-10 pulls to start it. When hot it always started on the FIRST pull. But, today I had to pull it 6-7 times on occasion when I stopped to empty the bag. It has a new spark plug and air filter. I also ran carb cleaner thru the gas tank at least twice since the mowing season began. Any suggestions would be appreciated !!