OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Victa Two Stroke Engines Victa 2 stroke cut off issues

After buying and installing a G4 carby kit recently, I was having issues with the ignition pins. It seemed that no matter how I fiddled with those pins, I either had no spark or I had spark and the cut-off would not work. I wasn't prepared to stuff around with it any more and went to JayCar this morning and bought a marine-grade switch. It has a rubber boot over a stainless steel toggle, and comes with the wires attached so that the ignition pins plug straight into the connectors. This switch needs a 13mm hole which is easy with a step drill.

Honestly, it's not worth stuffing around with those stupid pins in the G4 carby. Sooner or later they play up.

Marine grade switch from Jaycar


Drill hole with step drill


Plug the pins into the connectors


Tape the joints with pink electrical tape


Voila, job done!

Hi oztayls,

Nice little write-up there, good stuff.

Personally, I've never really had an issue with the carby and the cut-off switch. I don't really understand all of the issues people have with them and the cut-off. I know that lots of people have written on here extensively about mods you can do to them and alt. cut-off methods, I just don't get it, probably because I've never experienced it myself.

One thing I would say which is something that threw me off years ago, make sure that when you install the cut-off plug into the carby (The one that goes into the body, not the one that slides through the outside), make sure you use the plug grommet, not the one which covers the whole electrical connection and goes into the carby. The long type plug isn't designed for the LM carby, the short, plug-type is designed for the LM. Using the wrong plug will cause the cam to jam on the throttle and that could be causing you issues. If you use the long-type and as such the connector doesn't go into the carby far enough, you could end up with a cable with too much wobble/play on the outer side, meaning it might connect with the cut-off cable when you don't want it to.

Also, I believe the carby in question here is an LM carby, if I'm not mistaken. The LM carby replaced the G4, and the G4 was never available on the PowerTorque engine. From what I can see looking around, a lot of people make this mistake (Unless I'm the one who got it wrong for all of these years haha).

pau13z

The cut-off design is just so dodgy and depends on the rotor to move the +ve pin so that it bends and touches the ground pin. A hit or miss solution really. The thing should have had a simple cut-off switch from the very beginning. Who knows what the engineers were thinking, but maybe the bean-counters were not going to spring for a switch mechanism? In the end, their solution was a design flaw and a potential safety hazard.

Having said that, I didn't have this issue on my previous Victa 2-stroke, but I admit that I never needed to service the carby on that one. This mower was used by my daughter and is an older model that I picked up 2nd hand, and other than this issue, has always been a good performer and been reliable. So it does still get a tick for that!

Hi guys

I also have had few issues with G4/lm cut off pins, but when they don't want to play they can be a big pain. But I do greatly support Norms carby mod as it gives full throttle control, and his new kill wire method is very nice as well

I have always used the one that fully covers the plug as I find the one with only the small ridge is more problematic

Nice old late 90s vantage by the way (I see no decomp valve and red deck so I am assuming a Vantage like mine). I picked mine up from the tip full of new parts - but the guy taped the 2 kill wires together haha.

Hi all,

For more details comparing the G4 and LM, review this old post:

https://www.outdoorking-forum.com.au/forum/ubbthreads.php?ubb=showflat&Number=66125&page=all

The cut-out plugs I refer to are attached. If you use the long plug in an LM carby (All PowerTorque engines), you'll experience issues with your carby and engine cut-out.

The PowerTorque engine was released in the '80s. It's had a few minor updates to different components since then, including to the carby, but all Victa 2-stroke mowers made since the mid-late '80s (I'm not certain of the exact year) when the PT's were released have used LM carburettors.

Unfortunately, from what I can see there has been a lot of incorrect labelling of posts, images, and videos, relating to the LM carby, calling it a G4. If anyone out there, like me, looked at some of that material when they first started working on mowers and had issues with the "correct" parts, it could be that the videos and websites were showing and advertising what to do with G4 carburettors and not LM carburettors.

Finally, people need to make sure they're installing the 2nd wire correctly. When installing the wire in the carby, there are 2 hard plastic holes in the carby body. the connector needs to thread through the rubber grommet, then the plastic of the body, then the plastic of the body again, and finally the tip should be visible poking out of the rubber grommet on the other side. If that's not installed correctly, it obviously won't function correctly.

As an example of how many people may get this wrong, here is a video from pushmowerrepair.com:


Here's a list of things this video got wrong (At a glance, there may be more):

• It's an LM carburettor, not a G4
• He's using a long cut-out plug, not a shot cut-out plug
• He installs the 2nd cable from the wrong direction

Personally, I push the short cut-out plug into place so it's securely in the carburettor housing, then with a small amount of WD40 on the tip of the cut-out wire I push it through the cut-out plug. Once in and pressing against the plastic of the cam, I back it out just slightly. Install the dust boot, 2nd wire through the boot and body, out the boot, never had an issue

Cheers,

pau13z

So it should be a simple matter of trimming the Long plug? It’s still a crappy design when a switch would do a better job?

Yeah I believe you could simply trim the long plug to make it a short type plug.

Just because a switch such as the one you have above can do a better job doesn't mean it's a bad design. It could be argued that technically this is a switch as well, just with the inner workings of a carby mixed amongst it, and a single control to perform multiple functions. In that respect some would say it's more highly refined, performing 2 functions as opposed to just one. With the switch you installed, you still need the throttle. With the throttle/carby/switch, you don't need the switch you installed... Always another way to look at things.

Also when you say better, I'd suggest that it's simply less prone to faults and failures. As a switch that functions at an on/off level, a switch such as the one you installed is more definitive in a way. The throttle/carby switch still has an on/off, just with a higher chance of it not functioning as designed if not maintained, which leaves it at a disadvantage in a way, but again, mostly seen when it's not maintained, so ask... Is it a bad design, are there better switches... Or do people just not maintain things? Perhaps we are the ones who should look in the mirror. It's a throw away world now unfortunately. The result, people don't maintain things break, the product is blamed.

Yep, point taken mate. Nice comment. I'm also the first one to promote maintenance. However, 99.99% of mower customers are not motor mechanics, so I would venture that a system as imprecise as this, is a good candidate for a bad design label. If you design something for consumers who just want a reliable machine to mow their grass every weekend so that they can get on with the BBQ, then perhaps it's not a bad idea to have a proper switching mechanism in place. If it confuses 90% of engine mechanics, then it likely is not the best design.

I read lots of reviews for all sorts of things. The take-out is that people just want things to work when they need it to work. In a mower, it's a weekly thing, so maybe 30 times a year. That's not even a lot of use, compared to the household coffee machine. It's easy for us to say "ha, don't you know that it crapped out because you didn't maintain it?" Well, yes, but maintenance should be for the expendable components of machines, like filters, batteries, blades, fluids, starters etc. I would classify switchgear as parts that should last at least the life of a machine, and on the basis of 30 uses per year, a switch should maybe last 100 years. For instance, I restore vintage HiFi gear, most of which are much older than these mowers. I don't think I've ever had to replace an on/off switch. Capacitors on the other hand are quite another story!

You did good there oztayls the Victa design can only be described as crap and I believe was designed so the the Victa dealers would continue to have a supply of service work as there was little else to go wrong with the 2 strokes apart from people straight fueling them

I do die a little inside every time I hear about or see or even someone comments about straight fueling :-(

You may be correct about the design being bad, I'm not remotely doubting the possibility, as I said, it just hasn't happened to me so I don't fully understand it. Believe me, if that day comes, I'll give you the heads up so you can prep your "I told you so" post lol, I'm more than happy to eat that humble pie :-)

I must have 40 PT motors here that have been straight fueled

That's a worrying indicator Norm. No doubt it's more rampant than ever. That's their biggest weakness. Stupid oafs acquiring them.

It's a throw away, plug-n-play, leap before you look world. People have forgotten how to read manuals, understand their purchase.

I was doing IT work for a bloke in his home a few years back now, CEO of a company which had massive machinery producing products for them. When I was working away he was sitting there reading the operating and service manual for a newly acquired piece of machinery. I couldn't help but think to myself, that old timer would probably know more about that machinery than anyone else in the factory.

It's a cultural and mentality change for the worse in my opinion.

Maybe manufacturers should add some obscure hurdle to getting their equipment to work, and put the answer 3/4 of the way through operating and service manuals, make people work for the answer haha. I'd love to work for the help desk of that company... Hello customer, I see you're having a problem, did you RTFM?... RTFM?... Yeah.. Read the F#$@ing Manual?!.. *Hang up and love my job*.. lol

We're being populated by cockroaches.
My beloved Ford Falcons are being increasingly bought by young dickheads now because the Commodore is such a crapheap now. You see at the drivers for yourself. All young imbeciles. Makes me want to buy an import just so as not to be grouped with those rock apes.

I've loved all these comments, some good chuckles there. So true about the manual reading and built-in obsolescence. I must admit to picking up the odd mower from the footpath on Council cleanup days, and done nothing more than changing the air filter, clean the spark plug and wash the fuel tank out. Perfectly OK machines.

Now I have a different issue with my Victa 2-stroke which I've not encountered before, so hoping you guys can help. This mower is now only running with the lever in START and STOP position. As soon as I push it to RUN, the thing dies. I've had the carby off again to check that the brass pin on the end of the throttle cable is properly turning the throttle rotor and that the diaphragm isn't pinched and the grommet hole is sealed. I'm stumped.

Silly question but have you checked that the main jet and its filter screen are clear or tried a different spark plug ?

Cheers
wce

No, not a silly question, but yes I’ve thoroughly cleaned the carby. It’s as if the throttle control is upside down the way it’s working at the moment. I can’t work it out. I must have a gremlin in it playing silly bugga’s with me.

I just modify the carby and it allows me to control the throttle from the lever, done hundreds of them

Mmm, do you have a link to your mod Norm?

Hi oz,
there is a bit of reading but it is the only way I can get these to work consistently.
https://www.outdoorking-forum.com.au/forum/u...arby-repair-modifications.html#Post82288