# rebuilding a carb on a lawnmower



## lexmarks567 (Aug 13, 2006)

How hard is that. When i take the bowl off all I see is a float and needle that stops the flow of gas when the float rases up. What else is there to replace. heres the engine info

briggs and stratton 5HP model 129802 type 0680-01 code 95010859


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## rameam (Mar 15, 2003)

http://repairfaq.ece.drexel.edu/sam/lmfaq.htm


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## Soundy (Feb 17, 2006)

Most small engines like that, there's also at least one fuel jet.

Is there a particular problem, or are you just rebuilding it for something to do?


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## lexmarks567 (Aug 13, 2006)

mower won't start. Prime it it fires the dies. prime it 101 times does the same thing fires then dies was working fine 3 weeks ago then when i went to use it again it would not run. this is a replacement engine as the old one died last year. replacement engine lasted all last season and part of this season then quit.the engine is used and the carb was rebult before I got it.


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## Perfesser (Jun 2, 2003)

Sounds like a fuel flow problem. Plugged fuel filter, fuel valve closed...?
If the compression is low in an old engine it just can't pull enough gas to start and this trick will get it going:
Get a propane torch and open the valve slightly so you can hear the gas -DON'T LIGHT IT!- put the torch nozzle under the air cleaner and pull the starter. The engine should fire and it'll be running on propane; after a couple of seconds move the torch away and see if the engine continues to run. If it stalls the carb might be plugged. there's a jet in the tube running up from the bowl...Try cleaning it with a long pin or sewing needle; all it takes is a little bit of varnish (from old gas) or a bit of dirt to shut these small engines down.
There isn't much to replace in one of these carbs other than the float valve.
I have a tiller with a similar engine but my biggest problem is dirt dobbers building nests in the air cleaner.
Another possiblility - check the oil level and see if the oil smells of gas. This type of carb is prone to doing a 'dump' and filling the crankcase with gas and the engine will do just what you describe. Had that happen on a big mower and my generator.


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## Soundy (Feb 17, 2006)

I'll second the idea that it sounds like a clogged fuel jet. Priming it shoots a little gas into the venturi or intake to get it started; once it's running, the air through the venturi normally sucks gas up the jet out of the float bowl. If the jet is clogged, it won't get any gas to keep running.


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