OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Victa Two Stroke Engines Why won't my Victa start ????

Hi all,

As most of the regulars on this site will know that my expertise is squarely aimed at the Model 45 Scott Bonnar and Supercut cylinder mowers which are all basically powered by 4 stroke engines.

Well back at Christmas time I was going to pick up some electrical stuff from a guy in Plympton here in Adelaide when I passed a large industrial bin in the car park of a closed business. Beside it sat a lawnmower in pieces so I thought here's an opportunity to get a mower up and going and give it to someone that needs a working mower opposed to it going to scrap.

I got it home and just parked it under the trailer so it wouldn't get wet unnecessarily and thus I'd get to it at some later stage when I had a bit of free time.

Well as I said earlier in this post I'm a 4 stroke person and have never really understood 2 stroke and thus this would be a great learning curve at no expense out layed.

It had spark but no fuel was getting past the needle and from what I've read on Norm's posts about Victa Needles I can understand what he's referring to about quality control of those components. It took three needles for it to allow fuel to flow.

Finally sorted out the carby and was getting fuel and spark, but one component was missing.........compression ! My finger was not feeling any resistance whatsoever when pulling the rope starter and my understanding of the decompressor valve made no sense when comparing it to 4 stroke engines.

At my sons school they have a large skip to accept scrap steel to pay for their "Pedal Prix" entry that they compete in every year and the scrap pays for this. I noticed another Victa in really poor condition sitting in the skip that had such a badly rusted chassis but a complete engine bolted down on it, so I decided to take that rusted out piece of junk and compare it to what I had and the leftovers would go back to the skip.

The engine on the junker had great compression so I first thought about changing the piston over but once taking the original engines head off and looking at the bore which had quite a few gouges in it I decided to change over the complete engine and use all the best parts on one unit.The only difference I could see was the two different heads used. One (the original) had the de-compressor valve fitted into the head while the other (the donor) had the opening in the casting but not drilled out or tapped with a thread to accept the valve.

After putting it all together and a few pulls of the starter away she went, blew a lot of smoke in the first 3 minutes and then settled down with no smoke whatsoever. It starts with the feel of a four stroke due to no de-compressor valve but fires up on first pull every time now and no smoke.

My question is why did they produce a cylinder head with no de-compressor facility or may this head have been changed with a generic third party unit that gave you the ability to either run with or without the valve body fitted. Not sure what's the go, regardless it works great now.

Anyway here are some photos of the cylinder head fitted, the engine came from a Silver Victa "Hawk"




Now here's some photos of the piston from the original engine, any clues why there was no compression ??????????????




Not much problem with that piston at all eh ?

Just a heads up, the original engine had the much larger black plastic cowl that protruded right over the cylinder while the engine we can see in the photos had this much more narrow cowl. They are both Powertorque engines only the larger cowl had the words Powertorque in the moulding of the plastic while the pictured one doesn't mention the name at all and I feel that is the earlier production version.

Your Thoughts would be greatly appreciated.

Hi BB, never come across one without a decompressor, I can't imagine it slipped through the crack on the production line and there is a million different plastic cowls out there, I think they probably put a different cowl on for each mowing season so the could claim it was the latest model so after 30 years of production there is plenty to pick from. BTW good score there, that mower has years left in it

Hi Norm,

The original Cowl had the big fuel cap with the support underneath to hold up the larger fuel tank.

That piston would have to be one of the worst examples I've seen regardless of it being 2 stroke or 4 stroke. I guess this happens when you let a single mother loose on a lawnmower that says oil ? what oil ???, mind you there are plenty of mere males out there that wouldn't now the difference between a Ball Pein hammer and a Warrington, then add the words assembly hammer into the mix and they just haven't got a clue. Too many people out there now that are just so much a part of this disposable society and only know where the nearest Harvey Norman store is.

Cheers,
BB.

That cowl was used on the cheaper entry level models and the broader one with large easy to pour into opening, was for higher priced models. It was just a marketing ploy to differentiate the cheapest models. They made the larger fuel cap standard across the board later on.

BB I had one a couple of days ago Victa Tornado that my grandson brought around for me to look at from one of his neighbors, pull start was the problem. I had a quick look, nothing wrong with the pull start, did the usual checks, remove the decomp and put in a spark plug, no compression. I said to my grandson I think this has been run on petrol. He rang the bloke and then I get the story that his brother had borrowed it and put 2 tanks of straight petrol through it but as it still turned over they didn't think it was an issue. I haven't pulled the head off it yet, but I guess it will look like your pictured piston. Funny how it was the pull start that was the problem

This is symptomatic of four stroke being the norm nowadays. Would you run your car without oil?
A segment on the UK's Fifth Gear motoring show asked drivers if they ever checked their oil and nearly all said they never do and one middle aged bot said he never even thinks about the oil in his car engine. He just flatly said no I never think about it!

Yes it's probably the most common problem of how most Victa's die. They really needed to put a sticker or some type of moulded lettering around the fuel cap area saying "2 Stroke Fuel only" just like most diesel vehicles have "Diesel Only" on the fuel flap. I know dimwits still put 91 Fuel into diesels but probably not as many if there was no blatant warning at all.

I'd say that the engine which was originally fitted ran about two or more tanks worth through it so as to get like that.

Cheers,
BB and Victa every now and again, but very seldom.

The reason there is no decomp was purely a cost cutting measure by Victa to make the entry level models cheaper to manufacture but there is no performance difference between yours and one with a decomp valve.

If anything, it performs better a there is no possibility of compression loss due to a porous decomp valve.

Nice piston BB have seen a few like that myself,a little harder to get out.
In regards to the head without the decompression valve not a common head but not rare either. They did come out in the early to mid 90's.Usually on the boring base models the ones that were cheaper.I'd say it was due to cost cutting being cheap and saving on the decompression valve.
The cowls you were talking about were not what was mentioned but in fact from different time periods.The first one with the power-torque on the plastic came from the late 80's to early 90's,and the one you have put on was later and they still can be purchased now.
Your first engine could well have been the earlier powertorque and may have had more cooling fins on the engine block which would fit the time period for your first cowl.
Hope that doesn't sound to confusing.