OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Victa Two Stroke Engines Power Torque Leak

Hey guys,
I have a 92 silver streak with a power torque engine. I have had the mower for a few years now, and it has always been hard to start compared to other power torque engines I have used. These are the symptoms - Puffs a little smoke while pull starting from in between the cooling fins and the head and some fuel evaporates from the tank over a two week period.

Once you get it started, it will splutter and carry on, puffing alot of blue smoke until it builds up to full rpm.

If you have any ideas, please let me know! Thanks.

Are you saying that the head gasket is blown and leaking, between the cylinder and the head? I don't see how else you can get smoke puffs from that region. It seems to match the other symptoms too, more or less.

Sorry yes it puffs smoke between the cylinder and head. Is this a simple fix to install a new gasket?
Would this explain the fuel evaporation and hard starting?

It could also be the automatic decompression valve, are you clearly able to tell that the smoke comes from a gab between cylinder and head, or could it be comming from verry clost (the underside of the decompressor, which is the little mushroom like fella comming out of the head at an angle.)

It is fairly simple to install a new gasket so long as it has not been leaking long enough to have eroded the face of the head or cylinder. You have to remove the cowl to get access to the four nuts holding the head to the cylinder, then you just unbolt the head, remove the gasket, clean the surfaces of the head and cylinder, put a new gasket in between the two, and put it back together. However I'm not a Victa 2 stroke guy, so I can't tell you which screws to take out of what. Joe Carroll seems to be on line right now - he's the man on that subect.

Mr Davis: Yeah it comes from the top of the head, not the decompression valve. I thought it might be from the valve, so I replaced it but no fix. I have heard of people replacing the decompressor with a spark plug. What is the advantage of this? Is the sprk plug hhoked up, or is it just there to block off the gap?

grumpy: I understand what you mean. Should be pretty easy.

A blown head gasket would cause hard starting, and probably reduced power as well. I'm not clear on the fuel evaporation issue you have mentioned. What a blown head gasket would do, is increase the fuel consumption though.

It certainly does sound like the head gasket then!

there are 2 reasons to throw a spark plug in the decompression hole (no, it's not connected)

one, is as a quick way to diagnose the decompressor, if it works without, but not with, you need a new one.

The second is simply if you dont have the time/money/etc. to go about getting a new one, or fixing it up, the engine will still run normal, it will just be stiffer to start, and wont hit the same starting speeds.

I would say that the head is warped.


Pull the decomp and spark plug out.
Remove the head.
If the gasket is stuck to the block you are lucky, scrape it off. If its stuck to the head its about 10x as hard to get off. Then with no gasket put the head on the block, use 20 of the bolts turned in a few threads as a guide and see if the head sits flat or if it wobbles.


Either get a new head or good used one.


Or you could try flattening it yourself.
A bit of glass or clean flat steel. Lay out a sheet of wet/dry say about 320 grit, use either water or wd40 and get rubbing till its smooth and shines up all over the gasket face. How much care you take will show up in the end result.


I have often used the above method for getting whats left of the old gasket off the head. For some reason they can stick to the head like they are fused there. Using a scraper you just end up digging chunks out of the face of the head.




On the fuel thing.
If the tap is leaking and your head is warped, you will get fuel evapourating easily.
Pull the fuel line off with the tank full and check the tap does not leak. I had one that did that, too me a while to work out why the mower was a pig to start. Turns out it was constantly flooded.


Cheers, Bob.

No need to remove the cowl for a head-gasket change, unplug the spark plug lead, the hose from the decompression valve, undo the 4 bolts holding the head on and it will come off.

Clean the old old gasket off the block with a scraper, clean the head GENTLY (its only alloy its soft) I use a careful hand with a scraper, and chip away at the gasket.

Reassemble everything with a new gasket, do the head bolts up in a criss cross pattern, I usually torque them to a point where everything mates up and add 1/2 to 3/4 of a turn.

Wow thanks for the great responses. I will have a look into it over the next few days and report my findings. Is it possible to use RTV gasket goo instead of buying a gasket?

Not for a head gasket, Snap-on. Too much pressure and temperature. RTV can be quite good for making oil-tight joints when no pressure and modest temperature is involved, but not in this case. There are examples where people have successfully used no head gasket at all under favourable circumstances, but RTV would be almost equivalent to no gasket. It won't work on your Powertorque head.

True but i would remove the cowl. Check the O-ring under the starter and check in the bore, unless you are sure that its %100 good.

Id also undo the decompression valve before removing the head. No gasket gunk will get in it when you are cleaning up. If the head is no good its hard to hold the head and undo the valve without it being on the motor.

Ok so I removed the head and found that the head gasket was of course buggered. Went to the local mower shop and picked one up for $1.50. Cleaned up the head by placing 400grit wet and dry paper on a piece of glass and sanding it flat. Gave the cylinder a light sand too and put it all back togethor.
Started her up and it instantly revved higher than it ever did! Very happy. Thanks for the help.

You are welcome Snap-on. Some time you must tell us whether you've named yourself after a very expensive brand of tools. I have an old set of sockets bearing their predecessor brand (Williams) that are finally worn out, but after 60-odd years of daily use that is to be expected I suppose (I inherited them from my uncle).

Anyway, I digress. Thanks for reporting on the outcome - I'll close this thread.