What is cylinder compression for troybilt weedeater TB 20 cs

bad valve

Not sure... the 310 is 5cc smaller and fuel lines are different.

May be

https://www.ebay.com/itm/Carburetor-Carb-For-Echo-CS-440-CS-4400-Chainsaw-Walbro-WT-416-WT-416C/273678244421?hash=item3fb87e9a45:g:44oAAOSwpptcUVoZ:rk:4:pf:0

same issue with fuel lines but if throttle/choke links the same, save the $s. Look carefully close up images.

Spared my 20 yr old weedeater from garbage man with $15 china knockoff. Easier to start and uns better than ever before with OEM carb.

It could be as simple as a carb adjustment, fuel lines or you may have to rebuild the carb.

Do you have compression, a good spark and is fuel going into the cylinder.? Working on a solution.

remove the top cover. look inside while pulling rope briskly, you should see two dogs fly out and retract when the cord reaches its end. if not, check for dirt in the system and clean out. if no dogs, you will have to remove the system from the housing, be careful of the spring. check for any broken drive parts. also check flywheel cup for damage where the dogs come into contact with it.

I would have a cylinder compression done on the engine before spending any more money. It may be below 100 psi and will not run. Plus if your fuel mixture is over 30 days old I would mix up some fresh fuel mixture.
Or the diaphragm in the carburetor has become stiff and is not pumping any fuel.
Good Day.

Below are a few links that might prove useful. The first two are operators, and shop manuals for the 144. I briefly looked through them and they have engine related info. The third is just an exploded view of the engine.
Hope this helps.

http://lawnandgarden.manualsonline.com/manuals/mfg/troybilt/tb144_1.html

http://lawnandgarden.manualsonline.com/manuals/mfg/troybilt/4cycle.html

http://www.partstree.com/parts/?lc=troy_bilt&mn=21AA144R966+TB144+Cultivator+%282006%29&dn=769021900001

Go to troy bilt pony horse tiller pto manual owner cd. And you can locate the manual you are looking for.