Briggs & Stratton Engine Hunting + Cutting out
In the video you can see I have an Atco Royale B24 mower with a Briggs & Stratton Engine.
The engine hunts and after mowing for 5-10 minute will gradually (e.g. lower RPM slowly over 10-15 seconds) shut off.
The engine will only start and run with the choke closed. Even if I let it run for a few minutes and then open the choke it will cut out.
Also, although the throttle is open the engine only sounds like it is idling.
The spark plug is clean.
The fuel tank is full.
the air filter is dusted off with no big debris.
wondering if anyone has some ideas on what to try next?
see video, which shows the issue.
many Thanks, David
Forums
Thanks for the support and
Thanks for the support and tips.
The video is on the link in my original post.
I did start down the route of inspecting the carb. It's bolted to the tank with 3 bolts (two which secure the choke lever assembly and one next to the diaphragm cover) but how does it detach from the tank after that, is there a 4th bolt or should it release easily from the tank?
The engine has code 94092607 stamped on it as seen below if that helps with the anti-hunting mod thought:
As well as being fixed to the
As well as being fixed to the carb the tank has a bracket that runs down to the base of the engine with a single hex head screw fixing it to the engine .While the tank can be removed with the carb still bolted to the block its a bit of a fiddle especially with the engine still on the machine. The best option (imo) is to remove the two hex head screws (bolts iyl) joining the carb to the block, remove the single hex head screw at the bottom of the bracket , un hook the governor spring and remove the tank and carb as one unit. Depending upon your exact setup, you may have to undo / unhook some of the throttle/governor linkage. then you can get the carb and tank assembly onto the bench at working height and deal with it in relative comfort. Digital images when dismantling can be your friend at reassembly time.
Trying to avoid what looks like "unnecessary" dismantling will often end up just complicating matters!
Hehe, two Atco Royale's in a
Hehe, two Atco Royale's posts in a row! Mine was the other one! My R24 has a Techumseh engine instead of the B&S, but I'd agree with Wristpin that a damned good carb clean will sort it out. There are too many carb cleaning vid's on Youtube to choose from :D
Thanks all for the help.
Thanks all for the help.
the engine starts fine now!
During disassembly I removed a spring off the governer arm and I can't remember how it was orientated for reassembly.
Does anybody have a photo of that showing how it should be connected?
Drop off the carburettor and
Drop off the carburettor and fuel tank. Remove the carb from the tank and inspect the filters on the end of the two fuel pickup pipes. Remove the cover plate from the side of the carb ( a spring and cap will fall out from behind the diaphragm). On the other side unscrew the complete adjustable jet.( hexagon ) Behind it you will see a slot headed brass jet; unscrew it with a good fitting screwdriver . Then give the carb a thorough blasting with an aerosol of carb cleaner.
Reassemble with a new diaphragm and gasket between carb and tank and maybe one ( sometimes two) between the carb and the cylinder block.
Early in the life of your machine there was an anti hunting mod but by now your example either didn’t need it or has had it, so we won’t go there for now.
PS. No vid