Hi all
I'm fairly handy but am brand new to small engines. I was given a troy-bilt mower to tinker with. When I got the mower, it would not stay running for more than a few seconds. I got a carburetor rebuild kit and after a good cleaning and rebuild, I fixed that issue. It started quickly and ran well immediately. The next day when my son pulled it, it idled very low for a few seconds before dying.
Engine: 126T05 0475 B1
Mower: 12AG836E011
I discovered that if I moved the air vane manually to open the choke during this low idle that the motor would rev and run. It runs great once it is started. Realizing this is likely related to the air vane, I opened up the shroud to get full access to it.
This is where it got interesting. Having no idea how the air vane actually works, I was surprised to find the thermostat on the other end. (The thermostat does
appear to be working - it holds the choke open when it is hot and moves it back to closed when it is cold.) The nightmare started upon closer inspection of the muffler area. There was only one bolt in the muffler which I figured would be easy to fix by ordering a new bolt. After getting the shroud off, however, that whole side of the mower was black. I was not too shocked at this point figuring the second bolt would better affix the muffler in place and be an easy fix. After getting the muffler off for a closer inspection, I found what is in the attached picture. It looks like someone was trying to re-tap the muffler bolt hole and left the tap in the hole???
While not ideal, I cleaned the stray metal up around the hole so I believe the muffler will actually sit against the block where it is supposed to. I've checked and cannot see stray smoke coming out on the wrong side of the muffler. I do not believe that this is contributing to my issue at this point. I do realize that there could be compression issues brought about by this but it'll be a few weeks before I can get it to someone who may be able to fix this particular problem. I'm moving on hoping that I've got this problem "fixed enough" until then.
After cleaning up around the muffler, I played with the air vane a bit and it was sticking. I cleaned and lubed the pivot on the carburetor end and it is now pivoting freely.
As I said, if I force the choke open when it is starting, the engine revs and runs great. If I don't, it idles really low until dying after a few seconds. Once warm, the thermostat does kick in opening the choke and the engine restarts without issue.
- The carburetor has been cleaned and rebuilt
- It is new gas
- The spark plug is new and gapped to .030
- The air filter is clean
- The governor springs/linkage look good (in my newb opinion)
Can anyone offer me advice on fixing this low-idle problem?
Thanks!
Rich
