OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Victa Two Stroke Engines Victa mower, Only running when primer pushed in.

Hi all. I have a victa mower (G4 carb) that only keeps running if I keep my finger pushing the primer in. Won't run at any throttle position otherwise. Changed carbs, changed primer plate, still won't go.

Moe TheLawn,

I would be checking the 'O' rings both behind the spout and on the spout that the carby goes on just to start.

Thanks Bruce.

I actually have 2 x mowers doing the exact same thing. Checked o-rings in those locations on both mowers & even changed the spout from a known good working engine,(just in case there was a crack I couldn't see) but still the same.

Also checked the o-ring under the starter & it has a tight fit.

Any other suggestions?

Is the jet in the carb clean along with the little hole behind where they screw in?

Sorry, forgot to mention I tried the carby off the same working engine I tried the spout from.

Weird

Seems like a lean mixture problem, since it works when you prime it continuously. That means either poor fuel flow from the carburetor (as Joe said) or air leakage into the induction system (as Bruce said). Seems unlikely it is a blocked fuel tank outlet: if it was, the primer bulb wouldn't help. It can't be a needle-and-seat problem if a carburetor swap didn't help. (You did ensure that the swap carburetor worked properly on another mower didn't you?)
I think you need to go back to looking for induction leaks - if not into the intake tube, then directly into the crankcase. There are too many possibilities to go into them here. You said you had another mower with identical symtoms: have you made some assembly error on both of them?
A brute force diagnostic technique I've used successfully when desperate is a massive substitution process: swap major components until you find which one the problem stays with. For example, you could swap the whole cowl/fuel tank/fuel hose/fuel tap system. Then you could swap the carburetor and spout as a complete assembly. Then you could swap the base engine as a complete assembly. It has to be one of those three systems. When you know which one, work on that system only.

Have you replaced the fuel tap and also check the fuel cap as it has a small hole in it and if it is blocked then a vacuum will happen slowing the fuel flow to the carby.

Try taking the fuel tap out of the working machine or swapping the tanks to see if you problem is solved.

I'll try swapping the fuel tanks.

I haven't made any assembly errors, as that is how they were to start with

I don't need to keep pressing the primer, just have to keep it pushed in for the engine to run.

It must be in the engine somewhere, a leak probably.

Thanks everyone for the suggestions.