Hi, tecumseh hs40 carb. Took it apart when I got the bike and put it in the hot tank. Put all new gaskets, needle, needle seat, needle clip and made sure all holes in the jets and the vent hole were clear. Float is original brass that does not leak and does not have had in it. Been playing with the low speed air fuel mixture trying to get it right. Today I was trying to adjust and it stopped I put it up on my step that I use when working on it and gas came out of the vent hole for about 5 seconds. I would like to keep this carb because it is original to the bike. Any help would be appreciated
Tecumseh carb leaking out the side vent hole
- Thread starter Bbqman
- Start date
Sounds like you did a pretty complete cleanup but you didn't mention cleaning out all the carb body passages. It takes the smallest wire on the carb cleaning tool or wire brush bristle to get the low speed holes clear.
Sometimes after putting everything back together a piece of debris or old fuel line will get plugged in a seat or passage too.
Sometimes after putting everything back together a piece of debris or old fuel line will get plugged in a seat or passage too.
If you turned the low speed in while tuning it can cause a similar issue if the passage is blocked or needle/seat is too tight/plugged. I don't usually have to adjust too much from 1-1/4 turns out baseline.
If it's venting gas out the bowl vent while running or not it's most likely overfilling the bowl or not stopping fuel flow. Check the float level. Possible it was leaned or tipped to cause bowl to "spill" out?
If it's venting gas out the bowl vent while running or not it's most likely overfilling the bowl or not stopping fuel flow. Check the float level. Possible it was leaned or tipped to cause bowl to "spill" out?
What brand of rebuild kit did you use? I bought a batch of supposedly correct kits/parts a few years ago that had needles seats and bowl gaskets in little clear ziplock bags, the needles were shorter than oem and the rubber on the seat and the rubber was crap. It would make the needle stick, or it would not seat correctly due to the length, use and oem needle and they would not seal in the crap rubber seat 
.....Seats (oem) are directional as well, so if intalled upside down can cuase sealing issues. The indented circle side goes in/against the body of the carb, as well as making sure the little clip that holds the needle stays free upon install, those can get out of whack when putting them together or moreso when you are working on it with the carb installed on the engine still, Like when you drop the bowl to clean it out. and the float overextends. Of course don't forget to set the float lever as per specs, you can do it with a certain sized drill bit, My Tecumseh Carb service tool has a built in cutout/setting on the handle so I dont use the drill bit offhand, sorry.
.....Seats (oem) are directional as well, so if intalled upside down can cuase sealing issues. The indented circle side goes in/against the body of the carb, as well as making sure the little clip that holds the needle stays free upon install, those can get out of whack when putting them together or moreso when you are working on it with the carb installed on the engine still, Like when you drop the bowl to clean it out. and the float overextends. Of course don't forget to set the float lever as per specs, you can do it with a certain sized drill bit, My Tecumseh Carb service tool has a built in cutout/setting on the handle so I dont use the drill bit offhand, sorry.
What brand of rebuild kit did you use? I bought a batch of supposedly correct kits/parts a few years ago that had needles seats and bowl gaskets in little clear ziplock bags, the needles were shorter than oem and the rubber on the seat and the rubber was crap. It would make the needle stick, or it would not seat correctly due to the length, use and oem needle and they would not seal in the crap rubber seat .....Seats (oem) are directional as well, so if intalled upside down can cuase sealing issues. The indented circle side goes in/against the body of the carb, as well as making sure the little clip that holds the needle stays free upon install, those can get out of whack when putting them together or moreso when you are working on it with the carb installed on the engine still, Like when you drop the bowl to clean it out. and the float overextends. Of course don't forget to set the float lever as per specs, you can do it with a certain sized drill bit, My Tecumseh Carb service tool has a built in cutout/setting on the handle so I dont use the drill bit offhand, sorry.
.....Seats (oem) are directional as well, so if intalled upside down can cuase sealing issues. The indented circle side goes in/against the body of the carb, as well as making sure the little clip that holds the needle stays free upon install, those can get out of whack when putting them together or moreso when you are working on it with the carb installed on the engine still, Like when you drop the bowl to clean it out. and the float overextends. Of course don't forget to set the float lever as per specs, you can do it with a certain sized drill bit, My Tecumseh Carb service tool has a built in cutout/setting on the handle so I dont use the drill bit offhand, sorry.
Replaced everything again. Needle, needle seat. Cleaned every orfice, even under the Welch plugs No gas coming out the vent. Still runs like crap. Won't idle off choke. Going to take it down to a guy I know that works on small engines and wait for my ebay carb to show up. I don't know what else to do. I want this original carb to work.