This is called quenching the spark. But on an automotive engine with a higher compresssion ratio and under transient conditions the yellow spark can get quenched thereby causing a misfire. So you have to step up to a higher output coil such as a MSD or Mallory to overcome the quenching effect.
Because the engine compression is so high and the amount of fuel being delivered is so much, magnetos are used to overcome the quenching effect on the spark plugs. The first thing I check is the color of the ignition spark if I suspect an ignition problem. I use a spark tester. I use this for any gas engine…lawnmowers, chainsaws, generators and the like. Make sure the carbon center electrode is not broken and is present.
There should be a spring too. I tried this when I was young. I got the shock of my life and as thought about it then , Very stupid. If they are blue, the spark plug is ok. Else if the sparks are yellow or there is no spark at all then the spark plug is bad. What does a good spark look like? On an automobile ignition system the spark should be bright blue.
That's because the compression ratio is higher than that on an air cooled small engine. A low compression engine running at a steady state with a constant fuel supply won't quench even a spark plug with a yellow spark. How do you test a ignition coil? Connect your multimeter to the positive terminal or pin of your coil, and to the high output terminal that goes to the spark plug.
Most ignition coils should have a secondary resistance falling somewhere between 6, to 10, ohms;however, refer to manufacturer specifications for the correct range. Can a weak battery cause weak spark? Low battery voltage can also affect fuel delivery by causing the fuel pump to run slower than normal. This, in turn, causes, low fuel pressure and a lean fuel condition. How do you diagnose a bad Magneto?
The spark plug is fouled and shorted to ground or is open and the magneto, which is functioning normally, is unable to fire it. A typical bad plug will cause an immediate drop of or more RPM, at the mag check.
The key indicator is the suddenness of the drop. You have tried leaning and cleaning the plug to no avail. Subsequently, question is, what does a good ignition spark look like? On an automobile ignition system the spark should be bright blue. That's because the compression ratio is higher than that on an air cooled small engine. Compression ratio of an engine and the amount of fuel being delivered can have an effect on how well the spark plug fires.
This is called quenching the spark. Loss of spark is caused by anything that prevents coil voltage from jumping the electrode gap at the end of the spark plug. This includes worn, fouled or damaged spark plugs, bad plug wires or a cracked distributor cap.
Common reasons for weak spark are faulty flywheel magnets and faulty stator. A red or yellow spark is weak and probably will not spark in the cylinder. A blue or white spark is strong and has enough voltage to fight across the spark plug gap even under pressure within the cylinder.
How do you test a condenser? Switch the volt ohmmeter to the ohms position. Touch the red lead to the hot connector on the condenser. Remove the leads and reverse the placement to the condenser. The first step is removing the spark plug you want to look at. Follow these instructions on how to remove a spark plug.
Take the spark plug in your hand and begin looking at it for signs of damage. Look at end of the spark plug that was in the cylinder and examine it. You will likely see one of the following conditions. A normal spark plug will have brown or grayish-tan deposits on the side electrode.
Everything is just fine with your spark plug; you can reinstall the spark plug. Black, dry soot on the electrodes and insulator tip indicates a carbon-fouled plug. Black, oily deposits on the electrodes and insulator tip points to an oil-fouled plug.
Oil could be leaking into the cylinders, getting past pistons that are worn or valve guides that are worn. Finding the source of the leak is very important — consult a mechanic for guidance.
0コメント