Small Engines

I’ve got a rear tine Poulan Tiller that is 6 years old. I’ve never had a problem with it and it always stated up in the spring. Well three weeks ago I went to till the Garden and the tiller wouldn’t start. I pulled the plug, checked the gas flow and even sprayed carb cleaner in the carburetor….still nothing! Ok now what, I figured I would take the carburetor off and soak it for a couple of days. Still nothing! I was thinking it’s inevitable; I’m going to have to pay $100-200 to get this serviced. We’ll I’m the type of person who would rather sit on something and figure it out then to take it to a shop (just ask Katrina). I decided to give it one last look before I took it into the shop…The garden has to be tilled! I searched the internet for info on buying a new Carburetor for my machine and stumbled upon a YouTube video of someone cleaning a carburetor like mine. I watched and that night I stuck a wire in the jets and blew out the ports and low and behold it’s running again. Saved a chunk of money that can be used for something else now.https://www.youtube.com/watch?v=ArCAivgAyww

Great Job!!! and timely too! My Troy Built "Super Bronco" only runs on full choke, I'll try that trick!

Does your Poulan have a Briggs and Stratton motor by any chance?? Mine is a 6.5 hp B&S.

Same Engine and mine wasn’t as bad as full choke but last season I did need to run it at half to get a smooth till. Good luck and let me know how it turns out.

I will post the whole story here, when I find out if I am replacing the carb, or just "rodding out" the passages

Yesterday I finally worked far enough through my to do list to get to the tiller. Last year it would only run on half choke, so I pulled the carb off, sprayed it out with cleaner, put seafoam in the tank, along with the gas, same issue. Run only on half choke, and not for very long. So I borrowed one of dads tillers, and let mine idle with the seafoam running through it while I tilled the main garden. About a week later I broke ground for a flower bed, and it ran fine for 20 minutes. Then it would only run on full choke, and only as long as the engine was cold. So I parked it until I could get back to it. I used the parts cleaner at work, along with some still wire to clean all the passages, and used high pressure air to force out any obstructions that remained after that. Put the carb back on this morning, and it didn't really run right, at first. Had to have it half choked to keep it running. Then it started sputtering on half choke and didn't like it when I added more choke, so I backed the choke off and it smoothed on out. I was able to go over the main garden area without any issues. Time will tell if it's fixed or just decided to run for a while

well it seems that the efforts to clean the carburetor were not entirely successful. I have had to repeat the deep cleaning once and use spray cleaner every time I want to run the tiller for more than 5 minutes. There is a white powdery substance forming on the body (inside) of the carb. I am wondering if there is some kind of coating that had been put on when it was built that has worn off now and allowing aluminum oxide to form.

follow up / autopsy report

I gave up and bought a new carburetor. $60 bucks delivered to my door and 15 minute install. The tiller sounds and runs like it did when it was new.

Heavy build up of white powder (assumed to be aluminum oxide aka rust like stuff) combined with a rather acidic gel like substance found throughout wet passages (fuel areas) white powder of finer consistency found through all air passages. Also noted rust forming on metal screen part of old air filter. The fuel line barb is plastic, and pressed into a cast opening (no tool marks noted when this was removed). The needle valve has an o'ring for a seat, and a polymer tip on the plunger. The float pivot pin looks to be chrome plated and simply slides into a pair of drilled holes located in two cast in ears. The bowl that houses these is a stamped unit of some soft steel alloy. A hole in the center of the bottom of the bowl is where the main metering jet screws into the main carburetor body. This holds the bowl in place and meters the amount of fuel delivered to the main jet. Removing this revealed a heavy build up of gelled gas/water/and something. The unknown gel filled all passages in the metering jet and draw tube that leads to the main jet. This is the same condition cleaned out twice last growing season.

The new replacement from Briggs and Stratton has no plastic fittings, and the float valve and seat are made of brass.

So my current working theory (depending on how this unit holds up) is:
The blended fuel (some form of alcohol with a chemical cocktail blended with gas) seems to be hygroscopic (that is it attracts water) and as the moisture combines with the alcohol and separates from the blend it forms a compound that attacks the plastic. This plasitcizer gel is too heavy to move through the carburetor venturi and collects in the bowl and metering jet area. The choke circuit of the carburetor draws fuel from the bowl with a higher velocity air flow, and can therefore lift the heavier soup that will not pass through the main jet. The heavier particles fall out of the air stream and collect in the air passages.

At any rate, the tiller is fixed and running very well, the carburetor R&R was the best idea.