OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Victa Two Stroke Engines Victa 160 power stroke problem

I've got a victa 160cc when I mow the lawn it's does fine then feels like its revs harder than ever then dies. When you got to pull start again it's hard the first few times then loosens up like its too hot! I did put very old two stroke oil in but shouldn't be that it's oil still.

The phenomenon of revving up briefly then dying, when it happens to a 2 stroke, nearly always means it is starving for fuel. You might begin by disconnecting the fuel hose where it attaches to the carburetor, and seeing how fast the fuel flows out of it when you turn on the tap. You may have a blocked filter in the tank.

If the fuel flows freely from the hose, you need to take a look at the entry port to the float bowl, and the needle and seat. You may have a partial blockage.

The filters clean and flows good pulled the carby plate off and looks ok. I thought maybe piston slap? That's why is locks up so quick?

The symptoms sound like a combination of lack of lubrication, and perhaps lack of fuel (if the speed actually increases before it stops). I don't see a loose piston causing the speed increase, and unless the lubrication was bad, I don't think it is likely to cause seizure either, unless it was working very hard.

Has your old oil separated out from the petrol? If so, oil drops could be blocking the main jet and causing fuel starvation, while doses of straight petrol could be causing seizure. It isn't a perfect fit for the symptoms - I've never had full separation with any kind of 2 stroke oil, though I've had it with engine oil used to mix 2 stroke fuel.

Otherwise we'd be looking at something a bit obscure, such as broken or jammed rings causing intermittent seizure, and the speeding up before stopping could be in your imagination, due to the governor opening the throttle when it starts to seize, and making louder exhaust noise.

Overheating could also be an issue, however unless all the cooling fins were blocked I would highly doubt it, I have a victa 2 stroke utility at dads with no cooling shroud on it at all (think its pure lazyness I never refitted it but it is a junk mower) and after 2 summers it is still running strong with minor bearing rumbling.

So rebuild time? It does sound like it knocks sort of before it dies but it's so noisy that you can't really hear it knocking on idle

I've cleaned the fins too! I'll try fresh fuel and oil and try it again tonight. It only does it when I'm mowing but not if you leave it running flat out on the spot (no load)

How is the compression? If it is worn enough for the rings to be in terminal trouble, the compression should be pretty hopeless.

I've seen or heard of ancient, overworked 2 strokes wearing to the point where the rings were actually coming out of the grooves and jamming on the piston lands, but that was back in the 1950s when we all liked to get the very last out of our machinery before spending any money on it.

You put old oil in it??


Mixed accurately to 25:1 ratio???

With fresh fuel???
No ethanol??


It could be time for a rebuild.

By power stroke i assume you mean power torque??

Pull the spark plug lead off and tip the mower on its side, spin the blade plate by hand and see how it feels. Try wobbling the blade plate. Any slop in the bearings??

Pull the cowling and fuel tank off the top, undo the 3 bolts and remove the pull starter. Theres an o-ring under it that seals it, check its condition, it is essential that it is in good order and doing its job.

Then turn the mower over again you will be able to see and feel more.


Put the piston up the top of its stroke and use a torch to check in the bore.
Pop the clip off the top of the muffler and take it off, look in the exhaust port to check the bore and the edge of the piston.

That will give you an idea of condtion.

Yeah old oil should still be oil right? It's mixed properly but doesn't smoke that I can see cos the exhaust exits out to the blades. But I'll look at the stuff you said too thanks oh yeah it's a power torque beginners mistake haha

You are a legend, Bob... I was reading the earlier post and thought to myself....I wonder if it is the starter 'O' ring causing the prob...all the symptoms seem to fit!!
It is a continual "Power-Torque" prob!!

That oring looks fine piston seems fine and there's no play in the blade plate. Maybe 1mm of play on the con rod to the crank but that is all

To make sure we have all the obscure possibilities on the table, glowing carbon in the exhaust port or cylinder head, or a glowing spark plug electrode, can cause preignition that gives some obscure symptoms sometimes mistaken for seizure. For example, when it stops due to the preignition it takes up to a minute to cool enough to stop glowing, so when you try to start it, it kicks back or barely moves at all. I've known people to report their car was seized when all they had was hot carbon deposits.

Sorry i might have confused you re; blade plate.
Theres two bearings under the crank. Side to side movement in the plate is movememnt in these bearings, thats what i was suggesting you look for.


Is the underside of the motor Oily?? Above the flywheel fan??? All around the coil etc, it will have oil gunk all over it.


If the bottom crank seal is bad and/or the bearings are sloppy it needs to be rebuilt. Not expensive to do, not even technically that difficult. The 2 crank bearings can be got from any bearing shop. The bottom one is a special one made for Victas with the seal built in.


Con rod to crank sounds a bit sloppy.


Hardest part with rebuilding a Power torque is getting the big end conrod bolt undone. Some are easy, gentle tap with a pin punch is all it takes. Others are so tight they will destroy themselves, the specal tool, your knuckles and your will to live and still not budge.

Ok think it's just that old oil! But we'll see. Anyone put an expansion pipe on a victa 2 stroke?? Haha I like the noise

So yeah stripped the motor now the piston has seen better days! I bought a rebuild kit but the piston is not inclueded 😳 is it best to go with a victa or after market piston?

either/or, all genuine victa parts are cast in china now as far as I know, an aftermarket one will probably be also, boring out the cylinder is not usually financially viable, but so long as a standard one is within wear limits you can run it for a fair while longer as-is.

Yeah getting standard piston should only need a little bit of a hone and I'll tell you guys if it starts!

Got it going second start after a rebuild I'm very proud of myself! Just gotta ask bout replacing a cut out thing in the carb to a toggle switch I seem to remember joe talking bout it? Have you done it?

I havent done it, nor woould I these days, while the system they have is a bit crude they work well when they have good rubbers

I agree, once you get the hang of it, there not to tricky to maintain.

Have seen plenty of switches and what no used instead though, I found out from one donation, that the wire ports on an old round Bakelite light switch will accept the contact leads as is, without removing the actual contact posts.

I thend to keep one in the toolbox to help with diagnostics now.

Get a new rubber (i like the long ones). Poke it in the carb first. 5mm allen key helps, it wont want to go, it needs to be lined up perfect. Push the centre pin in the rubber. Slide the boot up, put the cross pin in.
Spark plug out of the motor and test for spark and no spark. Good to go.
It is easier to do this with the carb off the manifold.


Rarely do they not work as they are meant too.
A new rubber usuaully fixes them. If its anything else its usually me having to undo the bodge that someone has done trying to fix this issue the impropper way.

Bob.