OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Victa Two Stroke Engines G4 LM fix stuck cable on shut down

Hi Guys

I've had a lot of these Victa mowers with the G4 / LM carby and in the past 30 years a lot get a stuck cable when
you move the throttle control to off .

With the throttle control in the furthest up position the engine shuts down but then you go to move
the throttle control down , the cable won't move ,I can feel the outer cable trying to expand when I try
to move the throttle down but the inner cable doesn't move the carby cam.


The first thing I do is to lubricate the inner cable with (CRC or WD40) but even when the cable slides free,
the cable still gets stuck in the shut down position.


I know Norm puts a new stop position in the Carby that is adjustable so the cam doesn't move too far
in the off position so the cable can no longer get stuck, then he uses an aftermarket stop switch.

My question is ,are there any other fixes for this problem , any ideas anyone ? ,I have my own repair for this problem but I have never
seen anyone else do the same thing as me.( I will explain later)

What are peoples thoughts or ways that have fixed this issue.

I have wondered of other ways to fix this because I've never tried them.

1 Like will a new cable fix the cable getting stuck in the off position.

2 Does the cam need replacing because it's slightly worn.

3 Does the complete carby need replacing because of wear.

Any thoughts ?

Cheers
Max.

Hi Max, what I have been doing on the recent ones I have done, is just grind the humps off, seems to work better than cutting the ramps, it gives a slower more moderate throttle control. This gets rid of the sticking cable problem but then you have to put the washers under the cam so you can close the throttle. Because you have lifted the cam it then makes it difficult to fit the cable without putting a bend in the cable. To avoid this I just clip the cable in the first notch. When time allows I want to see if I can run a bit of weld on the can behind the lump so the lifter does'nt drop down and cause this cable sticking problem. Let you know how it goes. If Victa had only done that millions of these mowers would not have been thrown over the back fence in anger

G'day Norm,


As we know the lifter drops down into the cam near the off position for the cams choke position ,I can see possibly instead of welding the cam
you may be able to drill the hole for the cable in a different position ,this would advance the cam so it's no longer possible
to have the choke position near shut down position , the only thing is the factory kill switch would no longer work meaning
a separate kill switch would need to be fitted.(not a problem)

The throttle control would move less but nothing that would negatively effect anything.

With this cable getting stuck on shut down ,it's as if the cable is trying to push the cam from a straight position
instead of an angle, even with just the cam in the carby the cable gets stuck.

I just change the position of the cable,the way the cable pushes the cam ,quick easy fix.

Cheers
Max.

Hi Max,
That looks like a fix, not sure what the step in the cable is for but I guess I would work it out once I started playing with it.

Yes the step in the cable Norm works like a mechanical advantage ,less force to get the cam moving.

I've seen cars from the sixties that have the same step in heater vent cables.

Hi Max and NormK, This is a good discussion regarding the throttle cable stucked from off position. Redesigning and manufacturing a new product is always best to consider improvement and fix especially for the cam and not just exactly mirror the product with no difference. I'm always wanted to get a new cam manufactured but needs more information/feedback or a modified sample and how does it affect the engine performance or provide a solution. Giving the manufacturer the incorrect is very costly on tooling and molding. I have seen this throttle stucked and fixed them by filing the kill switch hump to make it more curved then plateau. This throttle stucked issue is not the lifter. To prove this, completely remove or pull out the kill switch contact from the cam and try if the throttle stucked issue still happening.

Cheers,
CM

Hi CM,
I believe a cam with the lump extended along the top edge will fix the problem. It also removes the need for the washers underneath the cam to lift the cam to compensate for removing the lumps that lift the poppet up fully. I need to put the washers under the cam so that the poppet closes fully which will stop the motor and then I use the adjuster screw through the cap to push down on the poppet to open it slightly to get the idle speed right. Problem I see with making a new cam is how many of these mowers are going to be around to fit them to. I have probably modified over 300 of these carbs but the volume of mowers I have been picking up over the last couple of years has dropped off a lot. I probably have 60 motors still here and plenty of bases but this is not going to be enough to consider getting a new cam designed

Hi CM,
Another thing I do is cut the spring that fits under the diaphragm cap in half so this reduces the pressure pushing down on the lifter and making it harder for the cable to move the cam