OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Victa Two Stroke Engines Need help with a 1986 Power Torque Engine

Hey, i picked up an old victa 2 stroke power torque engine from a mower repair shop's scrap yard, just the engine, and i cleaned the carby out, pulled it to bits, used kero to clean it, but i don't think i put it back the way it was or should be. The steam valve doesnt seem to move, or very little when the throttle is moved from start to run. I have made sure all the tubes go to the correct places on the carburetor.

What seems to happen is it will start after pushing the primer button in 10 times and will continue to run in an abnormal way for about 10 seconds

Does anyone know what causes this issue and how to fix it or where i can donwload an exploded drawing of this type of Carburetor.

The engine itself is a bit rusty but the controd, piston, and piston rings all seem new or atleast thoroughly cleaned, i am also getting good compression.

Thanks

Edit: i had a better look at this forum and found the exploded drawing, its similar.

Did you have the blade plate on the motor when you were trying to run it? As this forms part of the flywheel

Yes i did but i took the 2 blades off for safetly reasons

I also just had another go at it, i stretched the spring on the diaphragm that also pushes against the restrictor. This seemed to work, but i had no throttle control except shut off, and the engine just kept increasing its revs so i had to shut it down afraid it would sieze up. but during a few test starts i had to keep pressing the primer bubble to keep it going

Hi Webby293, It sounds like a workshop manual would come in handy....They are in the topic heading Questions on Lawnmowers and Engines, scroll to Parts Lists and Manuals. To access the area, you will need to click "My Stuff" on the toolbar above, scroll to "Subscriptions" and follow the prompts.Ezy Peasy

Ok thanx will do.
Also a quick questions, does anyone know what these engines normally rev at and also their HP, i know the torque and worked it out but it doesnt seem right-3.5hp i thought a 160cc 2 stroke would be double this

I'd rather not subscribe, despite the fact its $15, I dont like paying for things online as safe as it can be

Search youtube for victa repair, some good advice on there from a guy geoff390

Due to poor design a powertorque would be lucky to push 5hp, really it is just meant to spin a blade at 3600rpm. A 25mm mikuni carby and some other work can really wake the old victa motors up though.

I would be checking for a partially blocked jet or needle if you need to keep priming it to run,

The $15 contributes toward the upkeep of this forum, manuals are only there for people who wish to contribute.


Wow that was my 500th post...

ok thanx, i will try those things and post up on my results.

Nice on the 500th post lol

I've checked the jet and blown it out with compressed air, still no good, how ever my grandfather gave my his old briggs. 2 stroke, the cylinder is scorched and it needs to be bored out and a new piston and rings, but did take off the carby and put it on the victa, runs good now except it just keeps increasing the rpm when the throttle is fully open, i have not let it peak yet as im afraid it will cease up or blow the head. there is no adjustment screws only the idler.

If running another carb like that it should not be held wide open unless under heavy load, think of it like a cars accelerator, do you hold that wide open all the time? or open it as you need more power?

start off with it only just open and keep going until you get an engine speed you like.

Modern mowers nearly always have governors - in fact they've had them since the early 1960s. With your swapped carburetor you have no governor, and if you open the throttle with no load it is only the poor breathing of the Victa engine that keeps it from throwing its connecting rod within a couple of seconds. Back in the 1950s and before, mower engines tended to have even worse breathing than modern Victas, and weren't all that likely to scatter hot metal across the landscape if you opened the throttle without a load on the engine. Most 4 stroke mower engines used to be deliberately made with weak valve springs so they would valve-bounce instead of scattering, and of course they had a governor as well. 2 stroke engines often have the governor internal to the carburetor, which should make them less likely than 4 strokes to have the governor stop working - but having no valve springs, there is nothing else to keep them from over-revving and self-destructing.
You can use your Victa without a governor but it is likely that sooner or later (probably sooner) you'll over-rev it and break the connecting rod.
Apropos of nothing, when I was young there was a practice of having 'engine blowing-up parties'. An unwanted car engine would be set up on a stand, and run flat-out with no load until it blew. Meanwhile the lads would watch it and drink beer (mostly the latter). Of course being 4 stroke car engines, in those days they tended to just valve-bounce very noisily at around 4,500 rpm for a very long time. When necessary the sump plug was removed to hurry things along, but even then they usually just seized up rather than blowing up. Don't try this with a modern car engine - they don't valve-bounce any more, they rely on the speed limiter in the engine computer. Any silliness could result in a face-ful of fast-moving hot metal.

Grumpy, a great way we found to blow old commodore motors was to remove the carby and bend the steel fuel line to point into the inlet manifold, they went off with a HUGE bang.

Interesting, Joe - I don't know why they would blow until so much fuel got into the inlet manifold that they got a hydraulic lock during compression and broke the top of the piston or bent the connecting rod. I do recall a couple of hasty people at work doing something slightly similar quite a few years ago. Someone removed the carburetor from a V8, after pulling the battery lead, and went away to work on the carb. He'd left the car blocking the fire escape, so the next guy to come along opened the hood, banged the battery lead back on without looking at the engine, leapt in and cranked it up. The fuel line was pointed in just the right direction to drop part of the stream of fuel into the four large holes where the carburetor should have been, and the engine started. It ran very badly though, and the throttle response was non-existent, so the guy switched it off and re-opened the hood for a second look at the engine. By then there was a metre-diameter pool of fuel under the car. Nobody was very happy, but the two guys responsible were able to blame each other and that made them feel much better.

Hey grumpy, I would have loved to be a fly on the wall when that happened, I'll bet the language would have been enough to make a wharfie blush

the throttle only needs to be open a tiny bit to get to the speed an unmod vitca normally does, i also tried wide open but with the choke half shut, it run smoothly then, so i wander if it also has to do with it running too lean.

Darryl, the two guys came from different work areas so they chose not to interact directly. And I was a third fool involved: I saw the car blocking the fire escape and asked one of the motor mechanics who worked for me to move it, then left it to him how to do it. That made it more my fault than his. Then I got to discuss the matter with the guy who had taken the carb while leaving the keys in the ignition and the car in the fire escape. He did not work for me - it was all very stiff-upper-lip, kind of like a couple of dogs circling around each other.

Webby, see if the engine speeds up when you start to close the choke. If it does, it is running too lean without the choke. If it seems to run smoother but not faster, that is a different problem: 2 strokes usually run very badly with no load, and they can tolerate rich mixture pretty well. Half-closing the choke may just have the effect of half-closing the throttle.

ah k yeah having the choke half closed seems to limit the speed, sounds similar to when a victa carby is set to 'run' otherwise when the choke is wide open it just keeps increasing its rpm.

Webby,

Have you checked the fuel flow to the carby?

yeh, tank is above carby, fuel lines are clean and it flows well.