I can't get my Tecumseh series 1 carb to run rich, if I loosen the main adjustment screw (on the bottom of bowl) all the way out it doesn't run rough or smoke. What could be the problem?

Could be a partially plugged main jet.

This may not be your exact carb but this procedure applies to all Tecumseh carbs.


Click the below link then scroll down to pic 6 and 7 and make sure this small hole right at the threads is open.


http://images.search.yahoo.com/search/images/view?back=http%3A%2F%2Fimages.search.yahoo.com%2Fs earch%2Fimages%3Fp%3Dtecumseh%2Bcarb%26toggle%3D1% 26cop%3Dmss%26ei%3DUTF-8%26ni%3D20%26fr%3Dyfp-t-501%26b%3D1&w=640&h=480&imgurl=chuck.kichline.com%2Ffixit%2Fmowers%2Ftcarb %2FDSCF0005.jpg&rurl=http%3A%2F%2Fchuck.kichline.com%2Ffixit%2Fmow ers%2Ftcarb%2Ftcarb.html&size=81kB&name=DSCF0005.jpg&p=tecumseh+carb&type=jpeg&no=4&tt=74&oid=128a189d44ee0d14&ei=UTF-8

The hole is fully open, as shown in picture 6 and 7 in the link. My carb is exactly like the one pictured.

Thanks for the response.

Explain what the unit is doing and why you want to richen it up ?