lawnmower engine doesn't run properly

Old 09-05-01, 03:23 AM
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I have a Tecumseh lawnmower engine. The last few weeks it gradually has been having less and less power and it now shuts off after a few seconds. Pressing the choke seems to help. I tried Seafoam and that didn't seem to work since I haven't been taking out the oil or gas during winter.I have also replaced the air filter and spark plug. Any suggestions? Thanks.

[Edited by waynedo on 09-05-01 at 08:08]
Old 09-05-01, 04:34 PM
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Restricted Fuel Supply

Hello and Welcome Waynedo to the Do It Yourself Web Site and my Small Engine forum.

Check for a restricted fuel supply. This can range from fuel flow from the tank, through any inline filter, low fuel level in carbs with fuel bowls or a restricted carb of either bowl or diaphram type. Try using fresh fuel to flush out any stale fuel while checking fuel flow from the tank.

Also check the muffler for good exhaust flow. A damaged or overly rusted muffler may have internal damage causing an exhaust restriction. Exhaust restrictions can cause several problems.

It's possible the fuel tanks gas cap has a restricted vent.

To check this, remove the fuel line from the carb. Watch the fuel flow rate while doing this. If it diminishes over time as it is coming out, the vent hole may be restricted. If it stops totally, the vent hole is pluged. If all the fuel empties out, all is okay here.

If there is a restriction or blockage in the vent hole in the gas cap, the tank will drain until it pulls a vacumn in the tank. Then the fuel will slow down until it stops flowing. During the process the engine will lose the power and eventually die out.

Once you OPEN the cap or allow enough time to pass, the engine restarts because the tank once again gets air in it.

The carb could be gummed up from the stale fuel. In that case the entire carb will need to be removed, disassembled, cleaned out and reassembled with new parts from a carb overhaul kit.

Check the archives, within this forum, for more information.
There are several other postings and replies on the topic of carb rebuilding all with helpful information. Check the manufacturers online web site for additional help.

Regards and Good Luck,
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Accurate Power Equipment
Small Engine Service and Repair Technician.
Personal Quote:
"If it ain't broke, don't fix it until it is broken!"
Bare in mind my company no longer services nor repairs lawn and garden powered equipment. The information provided is specific and accurate to the best of my knowledge...
Old 09-06-01, 01:43 AM
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If it is a bowl type carb, which it probably is.
Remove the nut on the bottom of the bowl. It is
actually the main jet as well. There should be tiny
holes in the side of it, clean them thoroughly.
Also look for a tiny hole at the bottom of the threads
clean this as well. With the nut removed, gas should
dribble out. Look for water and debris in it, you may have
more water in your tank. Mark the bowl that the nut
was holding on so you can reinstall it in the same
position, and drop it down and clean it out as well.
Reinstall and try it out.

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