Join Date: Jan 2017
Location: Lawrenceville NJ
Rebuilt a carb, ran smooth, now runs rough, disappointing
I rebuilt a carb on a 10hp Tecumseh. The carb was in real bad shape sitting for years and partially outside, how long, I don't know. In Sept I bought a used 10/29 Craftsman that had very little use. You can tell from the scraper bar, skid shoes, and paint. What a nice machine with a 12" impeller, high front, very well balanced, like to say a dream to use but it is still a heavy machine to move around. Even when it's moving forward you know you have something powerful in front of you.
I took the carb apart including the small Welch plug on the side, soaked in Berryman's ChemDip for an hour in my ultrasonic cleaner, then turned the USC on for 60 minutes, let it sit for an hour and turned it on again for 30 minutes. Dipped it in water to clear out the solution. Sprayed it and the holes with compressed air. Used a torch tip cleaner through every hole. Blew it out again. Then reassembled with a new Chinese rebuild kit complete with welch plugs, low and high speed needle valves, rubber o rings, and washers.
Put the carb on the machine, started on the first pull. It ran so smooth, I didn't even need to adjust the low and high speed though I checked them. I ran it for about 10 minutes and it did not miss a beat. I turned it off and started it several times, always started with the first pull.
Today snow! Not much here in NJ, 3" but WET. I used a 5hp Noma to start with and then grabbed the 10 hp Craftsman to see how that worked. It started right away, ran smoothly, took it from the rear of the house to the front sidewalk and then it started running rough and kept dying. I kept restarting it and it ran rough and died. After 5 pull starts I checked the gas and it was empty. yea yea yea. No wonder it was dying. I put gas in it and it ran rough. While it was running I bled some gas from the fuel bowl using the spring relief valve in case there was water in the bowl and the same, ran rough. I grabbed another snowblower to finish the job.
What do I do? On a warm day I'm going to take the carb off, open the petcock and let some fuel from the fuel line into a clear soda bottle, let it sit and settle to see if there is dirt or water in the gas. I doubt it, the gas was gotten 2 days ago and used in 5 other snowblowers. Then take the carb completely apart and spray some carb cleaner in every orifice using those plastic red tubes attached to the carb cleaner, put it back together and see how it works again. If it fails to run smoothly, change the spark plug? Then put on a new Amazon carb I have! for this machine.
It does seem strange that it ran smooth the day I put the carb on for 15 minutes or so then the day of the snow it ran smooth until a few minutes later when I needed it for the front sidewalk. With being low on gas it seems like some dirt got into the carb and needs to be removed.
Any other suggestions?