Troy Bilt Tiller won't run more than 20 seconds

Hello
I have a Troy Bilt Tiller model: 21A24T1711. I am having an issue that it keeps running out of gas because I believe it is not refilling the bowl. The tiller was purchased back in 2018 and was used then and put away with gas in it. I know that's a bad thing. The gas did go bad and the carbuerator got clogged up. I tried cleaning it and I believe I cleaned it well but went ahead and bought a new one and replaced it anyway. It also has a new air filter, fuel filter, gas cap, spark plug, and fuel line. I clean the tank and am using fresh gas. I have verified that the gas coming out of the tank is good with no contaminants or water. I also veified that the OHV gaps is 0.005" as per the specification. After priming it will run for about 20 seconds. It will do this over and over. So I know that the engine will run. I know that it at least gets an initial prime. But why doesn't the gas keep up with the demand? I cannot figure this out.

I have included a reference pics.

Because I have done silly things, I thought I'd mention this. My tiller has a setting for start, and a setting for run. Does yours?  Are you switching it over quickly enough?

It's a long shot, but see if you can run it with the gas cap slightly loose so air can enter the tank.

I had a similar problem with my lawnmower once. Turns out the gas cap had a pin-hole 'breather' port that was plugged. It would run for maybe a minute before the plugged port created a suction-effect which prevented gas from flowing to the carb.

EDIT: Ah, I see you have a new gas cap. I'd still try running it with the cap off or loose adn see it that helps. Only other thing I can think of is you might have a bad float.

I did try running it with the gas cap loose. I also tried running it without the filter, making sure beforehand that the gas was clean. Neither made any difference.

I'm really scratching my head on this one.

Joylynn Hardesty wrote:Because I have done silly things, I thought I'd mention this. My tiller has a setting for start, and a setting for run. Does yours?  Are you switching it over quickly enough?

Mine has an RUN/STOP switch. It is definitely in the RUN position. I have been working on this on and off for three weeks. I always double check the switch before I try to start.

Thanks for the suggestion though.

Have a blessed day!

First of all-make sure gas is actually flowing through the new line and filter. Pull the line off the carb and gas should dump out (not just a trickle.) If you verify good gas flow.....
Take off the air filter and look inside the carb. BEFORE the throat of the carb will be the choke butterfly valve. (don't worry about the butterfly valve at the back of the carb, that's the throttle and is run by the governor). Start the engine, and make sure the choke opens. If you verify that the choke is opening....
Make sure that you hooked up all the linkages for the carb. If you didn't get the throttle linkages hooked up right, it won't run. Grab it and make sure it moves smoothly with some "spring" action. If everything is hooked up right.....
Make sure it's actually a fuel issue. Go get a can of carb cleaner/brake cleaner/starting fluid (whatever flammable spray floats your boat, really). Remove the air filter and start it up. As soon as it starts to die, spray some flammable liquid into the carb throat and see if it roars back to life. Don't just hold down the nozzle on your flammable liquid though, or you'll flood it. Little bursts of spray is what you want. If it's not receiving fuel from the carb), the engine will still run on your flammable liquid. If it doesn't run on flammable liquid.....
Then you're looking at an ignition issue. You'll need an inline spark tester. But....my guess is that your new carb is garbage. Is it a cheap Amazon carb, or an OEM carb? Amazon carbs are hit and miss with quality. It sounds like your carb isn't delivering fuel, not a spark issue. If you've got good gas flow and the choke is operating properly, there's not much left but the carb itself.

For what it's worth, I always store my small engines with a full tank of gas. I fill the tank with non-ethanol fuel mixed with Stabil, run it for 5-10 minutes, top it back off, and let it sit. Never had a problem doing that way.

I recently had a similar problem also on a Troy built. I ordered cheap carb off Amazon and was still having the issue. Turns out the new fuel bowl gasket wasn’t set properly even though I’d never opened it so a little air was getting in and causing it to stall after 10-15 seconds.

~ I’m assuming it was air I don’t know that for sure. However when I got that gasket set properly no more issues.

I agree with James. One of my first goto is blasting old shit with compressed air. Through the fuel line. Both directions. It does sound like water in the tank to me. Also the loose cap idea is a good one too. Air lock would act similar to fuel blockage and water in the tank

As I stated in the original post, I cleaned the gas tank and verified that I have unobstrucked flow to the carbuerator. I did completely clean the origanal OE carb and verified I can get ait flow through all passages. The frustraiting thing is that the OE and the new carb have the exact same results. The motor run for 20 seconds and stops. If I prime it again, it will do the same thing. It will keep doing this over and over. I don't have any problem getting it started. It starts on the first or second pull. It just won't continue to run. If I press the primmer a couple times when it starts to die, it will run a few more seconds. I can do this over and over. The only thing I have not replaced it the primer bulb. This is not like the ones with the two ports. This have only one port and a small hole in the middle of the primer button like the one in the picture.

Ok, I got the motor to run. I checked the idle fuel port and it seemed to be plugged. I also forgot to check the sparkplug gap. It is supposed to be 0.03" and when I checked it, it was less the 0.25. For those of you who don't know that means I will get less of a spark. So I set it to 0.03". The motor is very spurattic and not much power. It will contiue to run with the tiller engaged, which is a good sign. I am thinking about taking the main jet out of the one I ordered and replace the on in the OE carb with it. The thing I hate about this type of carb is there is NO adjustments you can make other than setting the idle, which this machine NEVER does. At least not to my memory. When you start it, it runs at operating speed all the time. Any suggestions would be great.

Here is a link to the motor running on YouTube.
https://youtu.be/3rweGsZDyJ4

Have a blessed day!