Victa mower won't start

[Durdge39]

Is your exhaust OK? Two strokes require a certain amount of backpressure to contain the fuel/air mix in the cylinder while the piston travels past the exhaust outlet. Usually this would only make them run like a dog while you still get some firing but it's worth a check. Also, are you using the right starting procedure? I have a thorough distaste for 2T as each one seems to have it's own particular starting method. Usually choke on until it fires then choke off with throttle cracked works for me.

One last thought is compression, while I wouldn't expect the compression to be great, if there is almost nothing you might have gummed up rings which are just letting the compressed fuel/air mix right back into the crank case.

Best of luck!
Tom.

[chrisb691]

Turn the bastard upside down so it thinks it's in the antipodes.

[MICKYG]

As you have checked almost every thing else CHECK ignition timing.

Regards Mike

[malb]

You mentioned the O ring between the starter and the crankcase. This indicates that the motor has a canterlever crankshaft, as Victa have used for about 30 years or more in their 2 strokes.

These also have a vacuum operated decompression valve mounted vertically in the head under the shroud. A spring and diaphagm system leaks off some of the primary compression when you are tryin to pull start the motor, once the motor fires and attains idle speed, vacuum from the carby works against the diagragm and closes the valve. If the unit has done a lot of work, or has had a few runs heavily overoiled, it can develop carbon buildup in the valve preventing it from sealing properly. Or the vacuum line that controls it can become dislodged or swollen over time, leaving it open via spring pressure.

The valve can be removed and replaced as a temporary measure with a spare spark plug to check whether the valve is faulty. However I know from experience that this should increase compression significantly, and significantly shorten starter cord life.
If swapping for a spark plug gets it going, look at replacing the decomp valve ASAP.