OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Walk Behind Lawn Mower Frames Victa Lawn Mower Frames Victa 2 stroke engine, broken cut out plug

My mower wouldn't start after I shut it down while I was using it. After cleaning up the carburetor, putting in new spark plug, new air filter and new fuel, it started but stuttled for a few seconds and then stopped.
While I was cleaning the carburetor, I noticed that the rubber plug into the carburetor where one of the cut-off cable goes is broken. That means that the carburetor is not air tight. My question is whether this matters. What is the symptom of air leaking in carburetor and whether this is possibly the problem that the engine will not run.
Please advise.

The cutoff not being blocked off would cause overevving rather than not running at all, I have a feeling that either the jet or where the jet scres into might have a minor blockage, this would explain why it gave you a weak little flutter then nothing.

I did put a wire through the jet when I cleaned it. Also, if I remove the spark plug, I can see petrol blowing out when I start it. Does that mean the jet is not blocked?
If notice that after the engine failed to keep running, and after I tried to start it a few times, it won't start anymore. Is it due to engine flooded?
When I test the sparks, I don't think they are blue. More like bright orange.
Will check the jet and the sparks tomorrow.

OK well by the sounds of that I would be leaving the spark plug out, with the throttle in the run position pull the rop a good 10-15 times, cleaning the plug and reinstall. It could also be worth checking spark with the old plug, it is not entirely unknown to have a new one fail.

What engine is it exactly? For the purpose of a test, make sure the two kill wires are completely separated, and try starting, To stop the engine turn off the fuel (but since you cant stop it instantly with the throttle be very careful).

It is a Victa Mustang 1987 model AU067A6.

I've found that I can start it if I have the level half way between Start and Run, at Run position, or even back to Stop (with kill wires separated). When I move it to Start position, it stutter and stop quickly.

Also, what should be the spark plug gap?

The boot is not what seals.
There is a rubber plug that goes in the hole in the carb that then the centre pin pushes into it. The boot goes on and the cross pin goes in.


I would say you need a new plug and boot.


Other than that it could be an adjustment issue with the cable. Thats an art to work out.
Or it could be a carb problem, diaphragm or spring issue.


Sounds a bit to me like it could be flooding.
Could be a spark issue, it should be blue.


Thats quite a few things so it could be anything realy.
Im not much help am i.

My local mower shop is now open after the break and I have bought a replacement for the rubber plug.

I opened up the carburetor and found that I have installed the diaphragm the wrong way (upside down). I correct the error and the mower now starts and runs.

I do not know why it will not start before as when I cleaned the carburetor, it was not dirty and nothing was blocked.

Even though it is now running, I don't think it is running as smoothly as it can, especially at low rev. However, I must add that it has always been like this for a long time. What can I do to improve it?

Pull the muffler off and check the piston. Pull the inlet off and check that side too. Not much you can do other than rebuild it if the piston is all scratched up.

I used the mower the other day. Initially it started easily with just one pull after I stopped the engine. Then something happened one particular time after I stopped the engine. I pulled the rope to start it and I heard a crisp pop and I thought I saw fueled air bursting out of the decompressor. The engine didn't start so I pulled the rope again many times to no avail. I then removed the spark plug, gave it a few more pull, put the spark plug back and then only it started.

I do not know how a decompressor works. Could someone enlighten me?
More importantly, could someone explain what could have happened regarding the engine pop I heard and why I could not start the engine after that?

Thanks for your help!

If the decompressor isnt closing the bang is from the burning fuel/air mix being burnt as it blows through the decomressor valve, Generally any modern one is a unit that is replaced as a whole. You can test it without the decompressor by putting a old spark plug in place of it and blocking the vacuum line that goes to it.