Engine Runs…Then Quits. Why?

Question:

My go cart will start up and run but after running for about a minute is shuts off.  Why?

Answer:

There are a couple of reasons why an engine will start up and then just quit they are:

– Carburetor Float Problem
– Bad Valve, either exhaust or intake, typically exhaust.

The latter (bad valve)  is the most common, especially if the go kart has been used quite often.  The constant acceleration causes the engine to not cool down properly and burn up the exhaust valve.

The reason why it occurs later in the running cycle, is because the “leak” opens itself up with heat.  Once the leak is open it gets to be real hard to keep the engine running.

A brief compression check when it quits will answer the question.

If the compression is still there you should feel it in the starter rope when you turn the engine over.   If the compression is low, the engine will just “flump” over with little resistance.

Valves can be easily replaced.  Typically the valve seat is not damage (because it is a harder material) but the valve will be worn out.

A new valve, some lapping compound can do wonders on a weak compression engine.  Be sure to get the correct valve clearance between the lifter and the bottom of the valve.   Also make sure the valve bottom is square, at not ground at some goofy angle.

You will be able to tell immediately that you have solved the problem because of the snappy compression and the quick starting engine.  Also you will get better power too!

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4 Comments

  1. don’t know if this will ever happen to anyone, but my motor had an off/on switch on it and somehow one of the connections on the back of switch (in this case the ground) came off and kept hitting the side of metal inside motor and would run and then stop.

    • Yes indeed, that can cause studdering engines. In general if the engine is running but studders…something is up with the electrical system. Check all switches and inginition wires for cracks or bare wire.

  2. I bought a gokart at a garage sale. It ran fine the first day but started to die. I don.t have a float valve carb setup so that cant be the problem. I changed the spark plug and it did not help. The compression seems fine when I start it. It will start relatively easy and idle but when its time to go it stalls. The spark plug i changed had alot of carbon black powder on it Just FYI. Any suggestions?

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