# Troy bilt trimmer wont stay running



## nbpt100 (Jun 1, 2015)

A Troy Bilt string trimmer was running great and all of a sudden it will not start. It catches and runs for 2-4 seconds and then stalls....with 1/2 or no choke the same issue.

I check for air leaks as best I can.....since it will not run very long I can't spray any carb cleaner around to see if it changes how it idles.

The rear of the crank housing looked like the o ring was worn so I assumed it may be leaking air.....I put some high temp gasket maker over it and re assembled and let it cure over night. It did not change anything.

I did open up and clean the carb....I replaced the diaphragm and gasket. The inside looked ok except the screen had some crud in it.

This is a Walbro WT 973 carb. I replace the lines and filter while I was at it. The new lines are semi transparent and I can watch the gas flow. I noticed when priming the return line always has a fair amount of air bubbles in it no matter how much i prime it. is that normal?

Also, I dont think this is a problem as it ran fine like this but the needle lever is below a straight edge when I place one across the carb housing....I always thought it should be even with the straight edge....not below or above it. It seems odd but it ran fine like that so I am reluctant to change it.

The Carb to intake o ring seems ok but it is hard to tell how well it seals. Why would it go bad suddenly? Everything is tight.

I can get a new aftermarket carb for about $16 so i need to keep it all in perspective. but before I order that am I missing anything?? Thanks.


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## bob1190 (Apr 18, 2010)

Check valves, welch plugs leaking. Suggest you buy new carb.


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