OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Victa Two Stroke Engines G3 carbs

Hi Gadge, just curious as to if you have any idea what causes spitback/cough through the G3 carbs. I usually just swap the barrel over and fit a new set of rings and fit a modified G4/LM carb and then they are bullet proof. Haven't bothered too much with the G3 because parts are readily available for the G4/LM and there is millions of them out there

That's why I will save any plastic carbs I can for their needles so I don't have to gamble on 'new' ones.
The G3 are glamorous but abit complex IMO. It's good to know the plastic can be made fantastic.
How is the Briggs needle programme going Norm?

Hi MF, needles and seats arrived a couple of days ago but I haven't had a chance to set any more up, the first one I did is working fine. Hopefully I will get a chance in the next day or so to set a couple more up. I have several primer caps drilled out waiting on the seats being fitted and then I have to turn the needles down and that is something I need to do without other things spinning in my head

The secret to these things, I find, is when a moment of free time comes along like a wave, just go and do one of those things bubbling in your head.

Spit back is usually caused by retarded ignintion leaking crankcase seals or rings I find G3 carburettors more reliable than Lm and G4 carburettors if you set them up correctly they are no issue at all. To set them up all you have to do is take out the beval gear hold the butterfly shut, then line the vane and throttle up with the thread hole for the gear cover then install the beval gear with one tooth left to the right of the small pinion gear and they are set.
Extra rpm can be gained with the toothed section below the governer spring or line up the factory lines.

What made Victa develop this more bloated design?
I suspect it was a combination of cheaper production and more modern hi tech looks to get the customers in. The T bar throttle was a clever way to remind people of the t bar automatic in a car which was taking off at the time, particularly on smaller cars.

The G4/LM carb is a clever design and functions probably better than any other carby I have worked on but it did have its design faults and there were factors at play as to why they had these faults

G'day Norm,
As others have said, this isn't in any way due to carby issues.

The G3 was a very reliable carby, with the only really failure-prone components being the plastic governor gears. Which were very easy to replace.

The only really 'head-scratching' fault I encountered with these, was a VC160 that just wouldn't reach the max governed revs range spec.

So I applied the 'full scientific elimination' process, and ended up replacing the main jet. Water in the fuel, while the mower sat idle over winter, had corroded the bore of the jet, so that it always ran rich!

Thanks Gadge, so it must be a compression issue if it isn't a carby problem, because by honing and fitting another barrel and piston with a G4 carb there is no more spitback and the motors run brilliantly

It was cheaper to make!

Even pressure die cast zinc alloy carby bodies require some finish machining, and the G3 had quite a few other machined components.
Contrast that with the G4/LM; the only machined components are the main jet and the brass needle seat.

I guess with their new U.S owners and sales to rival Holden, they could afford to develop this rather innovative approach to cost reduction. I think customers would have thought it looked good too.
I know I used to like the look of it as a kid. It really was very clever on a world scale, dodgy stop switch notwithstanding.

As a carby they are absolutely brilliant, particularly after they have been modified, kill switch abandoned and a Briggs needle and seat fitted

The G4/LM is great standard, so long as its reconditioned with NEW GENUINE PARTS , i have rebuilt well more thaqn a thousand of them over the years and apart from normal servicing or a fuel contaminant they are perectly fine. NO BUTCHERING REQUIRED

Joe I'm happy for you but I will continue to do it my way

Just to add a bit more to it Joe, the fact that you have repaired thousands of them proves they were very problematic, I do not expect to have to repair one of my modified ones ever again because there is nothing to go wrong with them now

How is the plastic piece that accepts the plastic carby attached to the barrel?
Could you theoretically attach a G3 or even a barrel/ piston type carby to a Powertorque just for fun?

I have seen a full crank where Bumps had bronzed a plate on so he could bolt on the G4 adapter from the later Powertorques which just bolt square on not with the offset as most have

I agree with joe, these carby's they dont give much trouble at all
99% of the issues I encounter are the primer has perished or split
The kill switches are reliable and trouble free they only fail because the rubber plug
Rubber goes hard or perishes.
Even with improvements you still have the most common issue of the
Primer cap and or o-ring failing.
No offence intended but I hate toggle switches used as kill switches
Seriously $2 fixes the issue.
As far as needle issues go I find the only time they fail is when you don't use genuine
Primer caps there is a massive quality difference

I'm more than happy with my fixes and I will leave it at that, each to their own.

The question is are genuine Victa primer caps and needles still widely available and if so, for how long now that Victa 2 stroke production has ceased.

The main Victa Gold dealer I get my parts from only supplies aftermarket caps and needles.

I did find some 10 year old stock of Bynorm primer caps and a 10 pack of needles, but still only had mixed success.

I'm also in favour of Norms modification to provide variable throttle. There's not much point running a big Victa 550 Pro flat out just cutting the lawn. It does the same job at 1/4 throttle easily. Probably the best bit is no issues!

A tip with the primer bulbs; if it has gone a bit hard, but hasn't actually cracked, there is a simple fix.

Douse the bulb with Armor-All, and let it sit for a few days before wiping off the excess. This does quite a good job of restoring flexibility.

Armor-All sure does!

This was the way the dealership I used to work at required all the new old stock vehicles to be detailed. You sprayed it all over and let it sit overnight. Then it would be wiped down in the morning ready for the salesman who would take it down a gravel road!

I don't know what the long term effect of the Armor-all on all the plastic and rubber was, but it sold them in a 1/3 of the time compared to being left un-detailed. It also meant the price could be bumped up a few thousand...

The primer bulbs on these are particularly robust, I find it very rare to come across a split or hard bulb. Must be made from some good material because some of the ones I end up with must be about 40 years old

Maybe it's the aftermarket ones that go hard? The original one on the Utility has split but is still flexible. However, it doesn't serve any purpose due to the split and requires extra pulls on the cord to start it. Still the needle doesn't stick like the aftermarket one I put on!

Is there a reliable method to test the needle for sticking by moving the float and needle by hand on the cap?

It is the only way you can test to see if it is sticking but this does not mean it won't stick when it is put back in. I had one that would work fine until you picked the mower up and tilted it towards you and this was enough to upset the level of fuel in the bowl and this was enough to make the needle stick. I haven't fitted a Briggs needle to this machine yet but I might do it tomorrow just to prove a point. It is a pain because unlike the earlier carbys with a tickler fitted you could actually see that fuel was flowing. With these primers it is a complete guess, and I would assume plenty of these mowers have gone to an early grave because of these dodgy float needles

Interestingly enough someone has just advertised Chinese made steel
Needles and matching primer caps on eBay

Well there you go, maybe I made enough noise for somebody to listen, they won't be available for a month or so, so I made the breakthrough on ODK first and mine are much better because the cost me $1.20 each

I've got a 'project mower' in hand just now, so that I can do 'how-to' write-ups on a few repair techniques; a 1982-3 season Mayfair MK326A1 full crank 160 Ute.

The primer bulb was a bit hard/stiff, so I gave it the Armor-All treatment [which I've also had occasion to use on hoses; e.g. oxy set twin hose], and it did work very well, as expected.