38racing wrote:I just had a briggs 12series quantum that ran fine last week refuse to run off choke today. I pulled the carb bowl and everything nice and clean. Sprayed the nut/jet with carb cleaner and air and it runs fine again. I was thinking maybe I should have a spare jet. You USA guys can get it for $11.00 . For me that translates to $15. cdn plus shipping. My local price $20 $CDN and that assumes I drive to the city and pick it up. (or order $100 plus)
You probably know this but anyway:
Most generally when I clean a carb and it then runs good for awhile I've found from experience that I have a better success rate if I also install a
new fuel line and add a fuel filter just before the carb. If I do this and the carb at a later time again needs choke to run the carb itself is usually shedding small pieces of trash or pot metal from inside the carb and replacing the jet itself will not permanently correct the problem because the jet itself is not the where the issue gunk trash starts, it's just trapping trash that is occurring upstream. If fuel lines are shedding trash inside of course a new carb is not going to run correctly for very long.
The Al Gore low emission carbs are leaned out so much on several that the carb/engine is so lean it's just barely getting by anyway. On the older adjustable jet carbs a guy could sometimes just make a carb adjustment and good to go.
I've seen few of the low emission carbs that has a adjustable low speed jet and the high speed jet fixed (nonadjustable) and just a slight adjustment of the low speed jet will take out the hunting surging at high speed. (usually just a 1/4 turn of the low jet and the engine will still idle good and not hunt on high or medium speed.