Briggs & Stratton 3.5 carb issue?

Question

I have a 1984 Snapper Hi Vac mower that has run great for 20+ years. Yesterday it started to lose power and now I had to remove the air cleaner and manually close the choke to get it up to speed but once I did the engine would sputter and stall any time I put a load on it. It seems like the choke is not reacting correctly and flooding the engine but I really have no idea. I changed the oil and it run fine (and fast) with no load on it so I can't blame the spark. The mower has no manual choke control. Any ideas? Thanks, Jopa

Answer 1

Well like you said its a 24 yr old mower it may be time to get it serviced by a proffesional

Answer 2

That engine has the carburetor fastened directly to the top of the fuel tank.  There is a diaphram between the carburetor and the fuel tank along with a gasket.  Chances are the diaphram is tired and may have a hole in it.  For about $5.00 you can get a new diaphram and gasket from any small engine repair shop.  Take note of the springs and rods that attach to the carb before you remove it.  You will have to take the fuel tank off and than take the carb off the fuel tank.  While you have it apart, clean the carburetor and the fuel tank.  It will run like new.

Answer 3

A good chance that the throttle body shaft has worn around the carb housing, and you are now sucking air around it.

Several ways of fixing it. Repalce the carb. Take it to a repair shop, and have thme install an oversized throttle body shaft, if one is available for your model.