# Tecumseh 5hp engine runs rich



## Country Boy (Mar 18, 2010)

Been messing with this one for several hours yesterday and today at work and its really driving me nuts. It came in running rough. I pulled the carb bowl and found some dirt in it, so I flushed it and the jets out and reassembled it. Also installed new spark plug. Still rough. Seems to be running rich (non adjustable carb). Pulled the carb and cleaned it, then installed a new needle and seat kit along with a filter in the line. Still rough and rich. I noticed leakage around the head gasket, so I did a leakdown test. Found a tiny bit of leakage at the gasket, but a ton of leakage past the intake valve. Pulled the head and lapped the valves, installed new head gasket, cleaned up all the carbon in the combustion chamber. Reassembled. Still rough and rich. I checked the spark with my spark tester, and it is steady, strong, and bright blue. Took carb off and disassembled. Dropped in the soak tank overnight. This morning I reassembled it again with a new float and all new fuel lines. I also dumped out the gas tank and flushed it and filled it with fresh gas. When I went to start it, it wouldn't start. No gas to the carb. I traced that to the filter. It appears it suddenly wouldn't let gas through, even though it still looks clean. I swapped in a different style filter (screen instead of filter material) and gas flowed fine. Put it back together and started it. It ran smooth as glass, well for about 15 seconds, then it started running rich again, but it sort of eased into it, running worse and worse over maybe 30 seconds until it was just as bad as before. It is blowing black smoke when it surges, and it makes the air in the shop burn your eyes after less than a minute of running, so its getting too much gas for some reason. That carb is clean as a whistle, and shows no signs of any varnish from step one. Any other ideas to check?


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## Country Boy (Mar 18, 2010)

Oh, and here are the engine numbers:

Model: TVS120 

Type: 63111F


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## Country Boy (Mar 18, 2010)

Just a quick update... I pinched off the fuel line this morning and tried running it again. It ran rough for about 15 seconds, then started to run smoother, then suddenly took off and started racing before shutting down (ran out of gas). I have a "Fuel Well Spacer" on order for the carb because I don't remember seeing it in there, and it shows one on the diagram. I also ordered a new main jet in case someone messed with it. I should know more on Thursday when I get back to work. This thing is just acting odd. It has 125 psi compression and the leakdown is minimal now, so its not a cylinder or valve issue. Its definitely a fuel issue due to the chalky black soot that keeps building up on the plug and the black smoke it blows.


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## Country Boy (Mar 18, 2010)

Well, I finally got it running. Ended up pulling a carb from a much newer junk engine and putting it on there. Ran like a top. I can find nothing wrong on the old carb. Its clean as can be, it has all its parts installed, none of the jets have been messed with, and I can find no cracks in the housing, yet it seems to dump excess fuel into the engine but doesn't run over or leak. I had cleaned and rebuilt that carb half a dozen times, and it still wouldn't work.


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