OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Victa Two Stroke Engines Victa Won't Rev Fully

Hi there guys,
I recently fixed up the carby on a Victa Powertorque lawnmower with parts sourced from this website (great service BTW). The motor starts first pull but won't rev beyond half throttle. What could be wrong? Is it easy to fix?

Cheers, Mark

Mark,

If you have done work on the carby maybe the throttle cable has popped out of the cam or the diaphragm is not seated properly and then again if it has a white poppet valve it could could be set in the wrong position.

We need a bit more information as to what you have done to the motor so that we can give the correct advice.

Hi Bruce,
it doesn't have a white poppet valve - it is black. I replaced the primer bulb and the plate that sits on the rear of the carby the Restrictor?

Cheers, Mark

Mark,

Can you tell me what you have done to the machine i.e. striped carby, replaced 'O'rings, replaced air filter. Step by step please.

The information you are supplying is making it hard to give correct answers.

Hi Bruce,
I stripped the carby and replaced the fuel primer/white plate and seal, fuel line and new spark plug. I did not change the air filter or the o ring that seals the carby from the induction manifold. I've pulled the carby off this evening and found the o ring on the induction manifold broken. I'll replace it tomorrow and see what happens.
Cheers, Mark

There are two other O rings that give trouble: a second one in the intake pipe, and one under the starter on top of the engine. You should check all of them.

Hi, I replaced the o ring between the carby and inlet manifold but when I stared her she kept revving really high and then low over and over. When I tried to open the throttle she died ...do you think it is terminal?

It sounds like lean mixture, which causes the governor to hunt, and in extremis causes stalling. You need to look for air leaks, blockages in the fuel tank or feed hose, or malfunctions in the carburetor. You did not reply to my warning about the other two O rings that often leak and cause the kind of problem you are having.

Hi Grumpy,
I've replaced the one on the intake pipe but can see the one you mean under the starter on top of the engine. The starter on this model is on the side. I'll pull the carby off and check fuel filters etc. Cheers, Mark

Okay,
I think I had not put the restrictor car on correctly. She is running well but revs when the throttle is fully backed off in the Stop position then when I push it forward to the Start position the revs drop to idle and then pick up again when I go to full throttle. Is this just a throttle adjustment issue?
Cheers, Mark

PS I just cut the lawn and it was fine ...just this weird throttle issue.

It could be a throttle cable issue, or a carburetor assembly issue. This is one for Bruce or Joe Carroll - I don't do plastic Victa carburetors.

Hi grumpy, as I remember the early alloy Victa carbys were very easy to fix; these plastic models can be very tricky to work on. Hopefully Bruce or Joe will have the answer.

I also have a G4 with the starter on the side. I stripped and cleaned out the carb and it fired straight up. (well it did once i worked out i forgot to fit the spring under the snap on digafram cover) It does the same as the above, half throttle is the lowest revs and either way it revs up a tiny bit more.

@Rainbird, something i have found a great help is fitting a new rubber gromet that goes on the stop pin. Makes it so much easier to fit the pin and have the stop switch working propperly. Could also eliminate a possible vacuum leak and stops the throttle backing off that extra tiny bit that can be enough to let the throttle cable pop out.


Im having a similar issue with a power torque. It starts and revs at one speed. Up to full throttle and it stays at the same speed, back it down to the choke and it coughs a bit and blows a bit of smoke but still runs at about the same speed.
I have another 2 carbs i stripped and cleaned i was going to try one of them.

What is the correct position for the white needle to go in?? I did notice that there is a cut out on the back of the needle. Best i can tell the bodys with the white needle have a white tip on the fuel outlet into the carb throat. In the black needle ones it is the same plastic as the rest of the carb body. Does it matter which needle is in which carb?


Cheers, Bob.

If the white needle you mean as in poppet valve (white plastic valve that almost looks like a car engine valve) I usually set with the C pointing toward the spray hole from the primer cap side)

If it is a powertoruqe less than 10 years old, I have found a lot of them have never ran properly except at on full throttle, I have one that I have owned from new at my fathers place that has never been 100%. The new generation powertorque motors are chinese made and I cannot say much about them that is good apart from they seem a lot quietr than its australian older brother.

According to the victa manual you cannot swap the black needle for the white needle but I have not found good reasoning not to. However if the original poppet valve is insterted correctly and the rest of the carb is put together riight it shouldnt make much of a difference.

Thanks Joe.
I just had a search and a look about. I found the C info and A and B are richer or higher revs.

I think i may have to check a few O-rings, the two inlet mainfold ones and the starter one too. Will do the same with the inlet on the G4 full crank.

I am thinking that all the mowers i have here are older than 10 years.


Thanks, Bob.