OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Victa Two Stroke Engines victa saberwill only chug

HI
this is a great site
I have a victa saber 160cc mower that stoped wile mowing,ti wouldn't start again.
I have pulled the carby apart twice (before finding this site)and it will only chug for up to 30 seconds then stop.
spark is fine and fule flow into carby is fine.
I have cleaned the spark plug and tried it with no air filter on and new fule with no change.

any one got anny idears
thanks
SB (smallbear)

G'day smallbear. I'm no expert around here, but I'm pretty sure the other guys will ask for the model / serial numbers and pics if possible so they can give a more detailed answer.

I've had lots of fun and games recently with my ride-on due to a sheared flywheel key after running over a pair of pliers left in long grass. The flywheel being out of alignment threw the timing out, resulting in similar problems to what you described. (It also drained the battery and ended up blowing the con-rod and killing the bloody engine) Could be worth having a look and seeing if your flywheel key is okay.

Have you hit any rocks or hard objects with the blades lately?

Okay, sorry guys, over to the gurus!!

Dirty Berty, please don't be sorry you helped someone - that is what we are all here for. smallbear, you said it's a Victa 160 so it is presumably a 2 stroke, and probably a Powertorque, but we need to know specifically. A picture would be a big help, and we need to know what the labels say about the engine.

There is a good chance the problem is an induction air leak, especially if it is a Powertorque. However it is best to approach the diagnosis step by step. I do not think flywheel misalignment is very likely on a Victa 2 stroke, but we need to go through a rational process that leads us to the solution.

Thanks guys
it is really nice when people you have never met offer help.
I'm sorry I am haveing troble getting a picture.
on the front of the mower it has a sticker with
sabre
160cc 2stroke-electronic ignition

where would i find serial or modle numbers.
thanks
SB

Having seen a few victas in the past, there are two sabre modles, one is a cheap (crap) chinese 4 stroke

The other is a 160cc full crank motor (what you describe) I would be getting a diagram of the carby to make sure it is assembled 100% correctly before continuing wityh other problems.

Cheers Joe.

I need you to have a look at the bottom seal of the mower and see if you have moisture around it. If so that will be the problem you have and all you need to do is replace the seal which is quite easy to do.

thanks Joe and Bruce
I have found an exploded diagram of carby I will look at.
Bruce do you mean the seal that's between the case and the shaft that's underneath the mower?
thanks
SB

That would be the seal they wear iver time, especially if something such as rope or something has got wrapped around the shaft at one point or another..

Yes that's the one.

I removed the plate the blades are attached to so i could see the seal, I can't actualy see the seal but there is no moisture around the shaft.
i reasembled the carby, still no luck.
i have noticed when turning slowly there is a "air rushing through small gap" kind of sound coming from decompresor, is this normal?
thanks
SB

If you had a decompressor problem I'd expect difficulty starting the engine rather than difficulty keeping it going. If you want to eliminate the decompressor as a possibility you can just unscrew it and screw an ordinary spark plug into the hole so you can start and run the engine on full compression. That will also let you feel the strength of the compression.

Have you checked the intake pipe for leaks? Are you sure the carburetor float bowl is not flooding? Have you started it without the air cleaner? (It can chug and stop as easily from rich mixture as from lean).

thanks again for your help sorry it is takeing me some time to reply.
I tried replacing the decompresor with a spark plug and it still dose not run, there is alot more compresion with no decompresor.
I can't find any leaks in the intake hose.
it doesn't even fire and now I think about it I dont think it has since the first day when I could only get it to chug.
I have checked for spark a coupple of diferent times by removing the plug, conecting it to the spark lead, holding the plug against the head and turning it over.
the primer bulb is now split, fule doesn't leek out, should it still run with it split?
I have tried rotating the fule bowl cover a little clockwise and anticlockwise, still no go.
i have checked the brass jet and the plastic jet for blockiges by poking a small wire through them.

any other ideas
thanks
SB

Sb,can you still hear air gushing out when you pull the cord.i am wondering even with compression you might have a bad head gasket...ken

with a spear spark plug replaceing the decompresor and trning over slowly by hand, in one rotation thete is two spots witch have resistance to rotation the first being harder than the second, when pushing through the first spot i can hear a small noise of air squeezing through really small gap and sounds like its from inside the engine.
the other spot is not as strong and ends with a small pop.
does this sound normal?
thanks for your time and help
SB

It is normal for a crankcase induction 2 stroke to have resistance to rotation twice each revolution. One resistance is crankcase compression, the other is cylinder compression. If it doesn't have both, it won't run.

What you have described could be quite normal - compression always leaks away if you wait a bit - but it shouldn't happen noisily or quickly. As ken said, you may have a head gasket leak. If so you can probably locate it if you put your ear close to the cylinder head. It is also possible that you have a crankcase leak. If you have a crankcase leak there should be visible signs of leakage from the upper or lower crankshaft-to-crankcase seal. A substantial crankcase leak could cause your engine to lack power, be difficult to control with the governor, or even stop running.

It is normal to hear a slight pop when you turn the engine over, due the opening and closing of ports against pressure.

Outdoor King, the people who contribute to this forum and hindsight are AWESOME.
It is rare these days to be able to fix a household appliance, every thing seems cheap and made to be thrown away.
It is exciting to be able to fix my mower as i am very happy to say I have fixed my mower tonight.
I was so close to chucking in the towel and buying a new one, that would have been a waste especially since i heard that I, like most Australians are among the top 10% of the world's wealthiest people, being able to fix my mower helps me feel less extravagent and more able to share with the bottom 20%.
I'm raving, sorry, back to the mower.
from the advice I've read it seems that my problem was a seal or gasket and wanted to check this before dismantling the whole mower. So i tipped it up on its nose removed the carby, positioned the piston in the top of the cylinder and poured petrol in the inlet, half expecting to see it leak out of the bottom seal, I was suprised to see petrol running out from behind the flywheel.
I then removed the fly wheel to find the top seal had slid up the shaft.
I pushed it back down, reasembled the flywheel and carby, tried to start it and it fired once and within 10 minutes it was running, yeehah!
One thing I am wondering...with a spare plug in place of the decompressor and slowly rotating the flywheel by hand, I felt two areas of compression, would one of these have been a vaccuum when the piston came away from the top of the cylinder?
I guess if I had removed the spare plug and rotated by hand, I then would have felt no compression or vaccuum from the cylinder and because of the top seal, no compression from the case?
Thank you Dirty Berty
Thank you Grumpy
Thank you Joe Carroll
Thank you Bruce
Thank you Mower Man
I really appreciate your help.
SB

Any crankcase induction 2 stroke (in other words, almost all cheap 2 strokes) sucks mixture into the crankcase when the piston is moving up to the top of the cylinder (called the crankcase induction process), then compresses that mixture in the crankcase when the piston moves down the cylinder (called the crankcase compression process). Towards the end of the piston's down-stroke, the transfer port opens allowing the compressed mixture to flow from the crankcase into the cylinder. So, there is crankcase compression when the piston moves downward as well as cylinder compression when the piston moves upward. That means you can feel two compressions per revolution of the engine. Leaky crankcase seals allow mixture to escape during crankcase compression, and also allow pure air (with no fuel in it) to enter the crankcase during crankcase induction. So, leaky crankcase seals means the engine will run badly if at all.

If your top crankshaft seal has blown out once, it may do so again, so your problem may come back.