i have a victa commando with a powertorque engine which i inherited. a couple of parts needed replacing, which i did, reassembled the whole thing, it starts fine and runs at idle fine but when i push the throttle to full it cuts out, i've pulled it back apart and tried to find the fault but i have no idea! if i pull thye throttle back to idle it continues to run .
Sounds like its starving for fuel. You might try removing the fuel pipe between the tank and carburetor then turning on the fuel tap briefly to observe the flow rate. Make sure the engine is cool, you are outside, and you catch the fuel, for safety reasons. If the fuel runs slowly, you have a blockage in the tank outlet. If it runs fast, you may have a blockage at the carburetor fuel inlet, such as the needle-and-seat. You'd need to dismantle the carburetor to check that. Having said all that, there are people on this board with much more recent experience than I have. My two-stroke carburetor experience was gained in the days of Villiers engines. It was easy then: you just held down the "flood" button and checked how far the fuel squirted out through the drain hole in the side of the carburetor top. It took a few seconds to check, and only a minute or two to fix. Yes, we old guys get nostalgic. But I wouldn't have one of those lousy old engines in a fit, now.
Joe, when he comes back and asks how to service a Victa two-stroke carburetor I'll just fade into the sunset and leave it to you people who've actually done it.
cheers, i'll check that. the replaced perts were the o ring on the fuel chamber and a part in the carb which adjusts the mixture(not sure of the name) its a disc with a pointed piece coming off it which connects to a diaphragm. i've remover the air filter whilst i've been tinkering
That is a litre in 3 minutes, so if the engine needed all of that the tank would run dry in about 10 minutes at full throttle. It doesn't, so you have enough fuel flow into the carburetor. You may have loused up the internals of the carb, hopefully non-permanently. Alternatively, there is garbage in the carb, blocking something up. I'm sure someone will tell you how to put it together so it works.
Seeing that it's a Powertorque engine, I'd check to see if the starter O ring is not stuffed......in which case it'd be pulling in heaps of air leaning the mixture.
Please do not PM me asking for support. Please post your questions in the appropriate forums, as the replies it may receive may help all members, not just the individual member. Kindest Regards, Darryl
I haven't heard the way the engine sounds when you go back and forth across the cut-off point. Lean mixture is usually accompanied by a 'lean spit' as you gradually increase to the cut-off, and perhaps a bit of a hiccup when you reduce the throttle and it starts firing again. If you don't have anything like that, there is a possibility that the kill-switch is malfunctioning rather than it being lean mixture. If it is running fast and is killed by the switch, if you let it stop completely with the throttle wide open then take out the spark plug it should be wet. If it died of lean mixture the plug would be dry.
if i push the throttle to full and let it stop the spark plug is wet.(when starting from cold it runs on full throttle for about 5-10 seconds then spins down as if killed by the switch and gives one last cough just before dying) the little o ring between the plastic gooseneck tube and the cylinder inlet port had been seated wrong and was misshapen, have reseated it the best i can until i get another. needle valve is pointed end up,round end down. plate is horizontal, will go and check the valve now.
just had a thought-does it matter which way around the metal plate behind the diaphragm goes? it seems fairly obvious that it has to be the way i have it now but obvious isn't always the case?
If it runs longer cold than hot, and if it coughs before it stops, seems like it is mixture not ignition. I'm not familiar with that carburetor but I have the impression there is a priming bulb which shoots fuel into the intake manifold when you pump it. Perhaps you could try pumping this when it is in the process of cutting out, to see if it comes back to life? That won't fix anything, it just confirms it is purely a fuel shortage that is causing the problem. Once we confirm that, I'll retire to the sidelines.
If the bulb makes no difference, but the problem is fuel starvation, that would mean there's no fuel in the bulb when the problem occurs. 1. Does the bulb squirt fuel when the engine is not running? (I think you can see the fuel squirting by looking in the open end of the carburetor, where the air cleaner would go). 2. If you squirt a little fuel into the carburetor air opening when the engine is running and is in the process of quitting, does it enable the engine to rev up briefly? Naturally you need to do this test carefully, not getting any part of yourself in front of the open end of the carburetor, and using an oil can or something similar to control the fuel delivery safely. If you don't feel comfortable you can do this test safely, don't do it.
not sure what i've done but it seems to be running a lot better, wanted to cut out 3 times during cutting the lawn, but quickly kept going after a throttle change. the only thing i did was starve it of air. for no good reason i can think of i pulled apart the plastic flexi air hose from the rubber air hose to see how much air it was drawing, i put my hand over it, it cut out,i put the hose back together and restarted it and it seems to be running fine(better) i checked the carburetor hose connection and there was no obvious crap that had been drawn through.
i'm happy that its running but i'm still curious as to what it could have been!! any ideas?
probably a bit of crap in the jet, starving it for air will make it suck hard on the fuel dislodging the muck. I do this sometimes with dry briggs motors.
