How does compression ratio affect ignition timing?
The increase in compression ratio develops the flame speed due to increased temperature of cylinder gases which results in retarded MBT ignition timing.
What is the compression ratio of a spark ignition engine?
The compression ratio varies from 4:1 to 8:1, and the air–fuel mixture ratio varies from 10:1 to 20:1.
What is the maximum compression ratio of spark ignition engine?
Air is compressed much more highly during the succeeding compression stroke than would be the case with a spark-ignition engine, with compression ratios of up to 25:1 typical.
Does retarding timing use more fuel?
This causes your engine to use more fuel to compensate for reduced power. This can damage different parts of the engine. Low Power: Ignition timing that is retarded too far can result in the spark plug igniting the mixture too late. This can reduce the power of your engine.
Do you need spark, fuel and compression?
An engine actually needs slightly more than spark, fuel and compression to run. It requires a strong enough spark, at the correct time, to ignite the correct air/fuel mix delivered by the carburetor, a properly sealed crankcase (2 stroke), and strong enough compression in the cylinder to allow it to run correctly.
How to fix spark, gas, compression, ignition?
Then change it again, they are cheap! If you have fuel, compression and ignition…….at the right time……it has to run, it has no option! As Fish said check the flywheel key and the air gap between the coil and magnet if the above doesn’t solve the problem.
Why does my saw have spark, gas, and compression?
I have spark, and after repeated cranking the plug is moist with fuel, so I think I have spark, fuel, and compression, but it won’t even sputter, nothing at all. I thought about pulling the carb and doing a rebuild, since that’s fairly easy to do but I’m at a loss as to why this saw ran fine one day, then two weeks later wouldn’t even sputter.
Why does compression feel good in an engine?
Seized pistons can feel like compression is good due to the resistance in the cylinder that must be overcome, even though a compression tester will show the compression is too low to run. An engine actually needs slightly more than spark, fuel and compression to run.