12HP tecumesh in a Craftsman 38" cut mower


Old 10-27-09, 04:01 AM
Thread Starter
Join Date: Oct 2009
Location: Hampton VA
Posts: 35
12HP tecumesh in a Craftsman 38" cut mower

Help help,

I know my carbs and I have done everything on this lawn mower.

I got a call form my inlaws and they said he the rider is back firing and hunting. I said to myself easy fix. So I get there with my repair kit and start fixing. I get done and start it up and runs good needs the jet adjusted of course. Well it runs good and then stops. Now the little holes at the end on the intake side where dirty so I thought needs the welch removed and a real cleaning job done in this area. I also know it runs and runs good.

So the next day I get a rebuild kit and rebuild the carb from scratch. Take out the welch and install a new one and seal it, new float gaskets so on. I pop test the neddle IAW the manual. All good on the Carb. I then replace the spark plug, check spark and do compression. This thing is 20 years old and pushing 85 PSI on the compression.

Reinstall the Carb and it will not start and it does back fires a couple of times. Idle needle is one turn out from beginning, the high needle is also on turn out. The carb is tecumesh also with the high needle on the bottom of the bowl.

This thing will not start! What am I doing wrong?

Some one help me please!

Sponsored Links
Old 10-27-09, 05:26 AM
Join Date: Feb 2008
Location: usa
Posts: 755
The Model, Spec. and DOM numbers would let me know specifically which engine this is.

If no fuel is entering the combustion chamber my guess is float sticking or float height adjustment off. Adjust float height and polish sides of float needle and hole needle sits in. A Q-Tip with a little metal polish will work.

You did not mention you cleaned the carburetor so if you did not get an inexpensive can of carburetor cleaner and go at it. Spray every nook and cranny especially the main jet.

This link may help. Is the carburetor the same as this one? Notice all the small holes they point out. They need to be clean and open.

Disassembly of Tecumseh (Lauson) Series 3 Carburetor 632334a

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Thread Tools
Search this Thread
Display Modes