So you seem to feel it is an engine power problem -correct? Does it seem like a lean or rich issue? Yours may have an issue with the choke- so you should verify that the choke plate is open fully. Some of these had a choke wizzard that is spring loaded and do strange things. Have you ever dropped the carb bowl to check for water/ debris? Same thing when you do line service of any kind. A sample should be taken of the fuel and observed. Fuel cap venting?

Some easy things that should be done anyways would be to replace the spark plug and fuel filter plus drop the carb bowl and clean. Run fuel through the fuel line ahead of the filter before installing to allow any water/ debris held up behind the filter to exit into the pan. That way to you can confirm what fuel goes to the engine is clean and the flow is good. Know that the fuel pump on these can hold debris as well. This way you know where you start. If the problem continues, note if there is fuel in the filter or not when it dies. Things such as a vent plugged in the fuel cap or failed fuel pump. The ignition coil commonly will cause this condition too.

please help. have john deere lt133 . gas in oil. i put on new fuel pump. i bought new carb. sick of changing oil with gas in it. have fire flame coming out of muffler when shut off. it doesnt want to shut off . sick of wasting money please help.it lacks power when in use but it does mow. somebody said gas shut off(so i installed) but dont make sense if it has fuel pump. then after i turn it off white smoke comes off engine.

A little update to this project. I was able to remove the height knob and adjustment step gear so I am down to the blade height lever. Once that is out can look at prepping the frame. I was thinking this would be best done by sandblasting and may have it sent out. For a test, I purchased a siphon feed gun and blasted a few parts. One was the muffler as I figured the finish did not have to be perfect and the other was the front frame extenders. Frame extenders had a few rust spots that were easily taken care of. The blasting with my setup did not take the green paint off, but left a real nice finish to accept paint. The blasting did make the bolts, nuts and clip look great. I'm thinking small finish parts could be done with this setup. I blasted tteh muffler and shot with high heat silver (matched from a picture of a new muffler on ebay). It came out excellent. Stamped brand/spec name was very clear after blasting both hardware and muffler. So latest dilemma would be the decals on the frame and how to preserve/handle. The Id with serial number and blade height/safety warning label on floor of frame will be completely blasted off. I can probably get a generic decal for floor, but I am worried about not getting a new ID tag with correct serial number. Thoughts? ps. I'll post muffler picture in a bit...