OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Walk Behind Lawn Mower Frames Victa Lawn Mower Frames Identify Victa Pro 550

Caleb there is probably 10 different cams I have seen, Victa was obviously to solve the problems with them. The lobes I cut back are the ones the lifter runs up and down on, as you can see the poppet is shut and then it drops down sharply into the "V" so it goes full throttle. By gently sloping it back you can control how far you want the poppet to open and this controls the revs

Thanks Norm. I've just put the carby back together with a new diaphragm, primer cap & main jet. I'll let you know once I get it back on the engine how I go. Caleb

Something I forgot, the "C" on the poppet faces the inlet from the float bowl section

I've just re-fitted the carby. However, when I put the earth pin in with the throttle set to half way, it jams everything up. Is this because I am pushing it in too far?

As I said not one of Victas smartest bits of design work, get used to it you will probably have the carby on and off half a dozen times trying to get that sucker to work. Just pull it back out and see if it frees up but I doubt you will get it to work as a kill switch without replacing the rubber, but you have to leave it in there because without it the cam can come around too far and release the cable

Ok thanks. It still won't start. The oscilloscope still says the coil is producing 5KV but plug isn't sparking - even with heroic cranking. I guess I need to find another coil & module. I don't think they're going to be able to mow the lawn before Christmas at this rate.

But you had it running before so the coil and module should be fine, pull the kill switch wire that goes through the side of the carby, you can never trust those. Heroic cranking isn't going to help, if it doesn't want to start it won't

Hi Norm,

There is still no spark with the kill switch pin removed from the carby and isolated from any potential earth.

There is no resistance between the coil mounting and the spark plug.

However, there is also no resistance between the earth lead and the primary terminal on the coil - even with the primary lead disconnected. The resistance between the primary and earth terminals is 1 ohm.

This is very puzzling as I would have thought that would short the coil out.

I would also think that if the timing was out it would still produce a spark like a Briggs & Stratton will when it has sheared a flywheel key. However, Victas may be different.

The other thing worth noting is that the flywheel has a noticeable horizontal runout that runs to 1/4" on the flywheel rim. This seems to indicate that the crank has been bent.

Maybe this is the problem, although when I set the magneto air gap it was even on all three legs when spun past the two magnets.

Caleb

Ps. I can see why they go to the tip!
Especially as todays shop labour would be more than it is worth.

Not the timing because you had it running, only way to check if the crank has runout is at the nut, if that oscillates at all then you can tell the crank has issues, but you had it running and you didn't mention any vibration issues. At the moment the issue is with the spark which was working yesterday before you started to work on the carby. You are right, one hour in the shop would be a lot more than they are worth and that is without any parts. Problem is when you get them running they are much better that the Chinese rubbish on the market now, I had a mate ring me up a few minutes ago, his brother wants a mower, he had bought some Chinese thing 2 years ago and it has fallen to bits and he is not interested in going that path again

Yes Norm, I was telling the owner that although a new Honda is easy to start and quiet when new they just cannot handle the heavy grass like a 2 stroke. I can mow grass three feet tall in two cuts whereas the Honda mowers stall. Also, the trendy new John Deere ride-ons cant handle much more than a suburban lawn either.

The mower ran after installing the coil but after letting it sit under a minute it then required a good 30 or so rapid pulls to get it to fire again. I then dismantled the carby to see if this was the cause of the hard starting.

What I probably should do is put the carby onto the Power Torque engine and mow some grass to rule out any problems with it.

Yes the crank and the nut has a major horizontal wobble when rotated. I also can't feel any play in the bearings.

It does vibrate, but no more than the later Power Torque engine I use every week.

When it does go it will handle 1 foot tall grass without dying.

Unfortunately, the only spare Victa engine I have is an earlier full crank engine (with plastic carby) that I rescued from scrap a few years ago. It has the earlier magneto with points. The engine is currently dismantled as it was seized up when I got it.

If the old points type magneto on the spare engine still works, can the later system be converted back to points? Assuming the mountings are the same of course!

Another option is to swap the crank from the older engine if it can fit the later flywheel. Otherwise I could just reassemble it with a quick hone & see if it has enough compression to run.

Can I convert the older magneto to use the same electronic module as the later version if the points are past salvaging?

Caleb, so many questions my head is starting to hurt. Fitting the carb on your powertorque is a good way of testing it, but at this stage you are saying you have no spark and the crank seems bent.Swapping bits around can be difficult with the ignition, internal coils/external coils, how to mount the points, gets really ugly, if you were a bit closer the problem would be an easy fix because there is a pile of stuff here you could use, but a lot of the stuff here is pre plastic carb

Yes Norm, I cannot understand why there isn't any spark. It is becoming a major headache. I think the owner said last year it was away at a shop for nearly 6 months!!

Thinking last night, although the crank is bent, when it does run it runs really well when it starts. It just won't restart until you are physically exhausted from cranking it over. I normally associate that with 4 strokers as all the Victas I've used are generally reliable.

Thank you for your help with this as it is absolutely mind boggling why it runs well but hasn't any spark when trying to restart it. I wish I had another engine with the same ignition system so I could test it.

Another silly question, what sort of air gap have you set it at 10 thou or about that? I do have a few motors here pre powertorque with plastic carbs, but I have never even looked at any of them,I like the powertorques so I concentrate on them. There is no point in pulling a motor till it exhausts you, they will either start or they won't. The beauty with the powertorques is spark on them is usually very good and rarely gives trouble

Hi Norm, I have tried setting the gap to around 10 thou with a business card and also tried it with the armature legs just touching. I'll re-set it with a feeler gauge to double check.

Hi Norm, I've got it to go!

I took the plug out and sat it on the magnetos base plate and span the engine over with the air drill. There is a spindly little blue spark every 30 seconds when rotated at 800rpm. I then closed the plug gap down from 24 thou to 6 thou and now it produces a spindly blue spark on every rotation. It seems way too weak compared to other magnetos I've tested.

Now I'll put the decompressor back on and see if it'll re-start when cold.

It won't start with the decomp valve installed. However, there's fuel leaking from the head gasket so that probably explains why as the compression would be too low. Once the plug is wet, it won't go until it is cleaned with contact cleaner. Then with a few backfires, it eventually runs again. I could lightly flap disc the armature where the coil goes over to see if I can get a cleaner earth. Otherwise, the spark is too weak to support combustion. I guess the reason it will restart just after it has been turned off is the hot carbon deposits ignite the fuel & kick starts it until the spark can take over! A bit like a pilot motor on the old Cat bulldozers.

Edit: I've cleaned the armature and noticed it is spreading out at the back. Maybe this is the cause? I can't really fathom what the cause of the weak spark is. Cleaning didn't make any difference.

Pity, I have plenty of head gaskets here and that is most likely the cause of the no starting. A thin blue spark is all you need. The fact you have fuel coming out the head gasket indicates it has a lung full of fuel and you need to leave the plug out and give it quite a few pulls to clear the fuel out. Not sure what sort of material you have down there to make a head gasket out of, just to see if this is the cause. You did check that the decomp valve was working, I can't remember if we discussed that earlier, bit of tube on it and give it a suck and the valve should close, if not it is not going to work

Hi Norm, I can get a NOS head gasket in town. Yes the decomp valve closes and holds when on a vacuum pump. I'll try the head gasket next. I hate throwing parts at things as it gets very expensive!

Edit: what plug gap should I set it to? It cannot jump the gap at 20 thou with a clean plug.

Something is not happy if it won't jump a 20 thou gap at atmosphere pressure. I guess you could cut a head gasket from a Weeties packet, might not last but you would at least know if compression was the issue, oil it up both sides and see how it goes

Hi Norm,

I've cut out a gasket using thick gasket paper and PEP gasket cement. I then torqued the nuts to 15 Nm. It still won't start with the decomp valve fitted. When fitted with a second spark plug blanking the decomp port it will eventually fire as long as the plug is cleaned with contact cleaner every 3 pulls or so. When it does run it revs up to governed speed and cuts out and then it backfires and stumbles and then it blows the head gasket. It must have cut a groove in the head. I've made two gaskets with the same results. All I can do now is skim the head with some wet & dry paper and try again.

I found another coil & module, but it makes no difference. When I put the plug on the power torque engine and crank it, there is a nice blue spark. Maybe the coil isn't receiving enough magnetic induction. I can't get a new E armature locally to try out.

I wish the base enabled a power torque to be fitted.

Problem is as I said I have plenty of those motors with that bolt pattern but most need the pre plastic carby and internal coils/points and I'm out the eastern side of Melb. Don't give up on it because it will end up a good slasher/mower

looking at that barrel , my guess is your working with stuffed
piston, rings...

Hi Norm,

I also have a points style motor but the PTO end of the crank seems to be different to this one. It has the cup flywheel and the internal magneto with points and plastic carby. Maybe off a Corvette?

What is puzzling is that it should produce a spark as long as the flywheel magnets passes the armature. It only produces a spark occasionally when cranking but doesn't hit and miss when it does actually run. Maybe the bent crank is the culprit? Still it can run and handle a lot of load as I worked it really hard to see if it died.

I'm going to be out baling hay most of tomorrow morning so will have time to think on it!

I remember seeing an old green Victa with a catcher outside a scrap metal place and when I came back 15 minutes it had been taken. I've asked dealers and repair shops within 70 kms from here and strangely no one has a second hand or even a wrecked Victa for sale.

Caleb

Yes Squizzy they're fairly bad. Still I have seen old Stihl chainsaws that look far worse and can at least produce a good spark!

The odd thing is why the spark is so weak.

Two replacement coils and a new module hasn't made any difference, which rules that out.

Here are some pictures:

Some things to ponder...

What is the bore reject dimension? 3 thou like a Briggs & Stratton?

Also what should the ring end gap be?

Can you still get new cranks to suit?

Edit: Just noticed it says Power Torque key start. I must be getting brain fade....


This flywheel has magnets 180 degrees apart. The one I'm working on doesn't. Is this an update or for another model?

Note it has the ring gear for a side starter and the magnets are level with the fins, not underneath.

http://www.mowersgalore.com.au/spar...ay/4642-victa-power-torque-flywheel-key/

the top pic is of a powertouque flywheel, goes under the motor,
wont fit your 160. and man.....that bore/ piston is r#tsh*t,
dont waste your time till you can replace / bore those.
cheers pete

Pete, the issue with this motor at the moment is not the bore, it is the intermittent spark that is confusing, in the words of Julius Somner Miller, "why is it so" Any way I have plenty of barrels and pistons kicking around here as well as new rings so somehow we will get this back to its glory days. Do you know if the earlier impulse start barrels will fit the side pull, I'm assuming they will, because I have a pile of those here

Hi Norm,

Does the flywheel on the engines fitted with the impulse starter have a cup with a nut on top of the flywheel?

I've got a scrap Victa that was seized up and this one has a cup that goes on top of the flywheel. Visually the barrel looks the same. However, the crankshaft is tapered to suit the older flywheel with the internal magneto and won't fit the later external magneto type flywheel. See the pictures below:

Flywheel off older internal magneto engine:


Comparison between older crank on left:



Comparison of older barrel on the right:



Once the flywheel nut is loosened, there is a noticeable wobble between the flywheel & the crank, which would no doubt upset the timing quite a few degrees depending on where the flywheel was sitting on the shaft when the nut was re-tightened. The flywheel came off the shaft with very little effort. Note the aluminium flywheel mounting doesn't show any signs of fretting against the steel shaft, even though it is a loose fit.



When testing the runout of the flywheel end of the crankshaft with a dial indicator, it indicates a deflection of 40 thou when rotated! Maybe this is due to a mechanic levering off the flywheel unevenly?

The crankshaft end float is 2 thou. This amount of float seems acceptable.

What is unusual is that someone has applied liquid nails over the top two crankcase bolts. Whether this is to fill a crack or to stop the bolts from turning I'm not sure.




The flywheel magnets are flush with the aluminium casting. I don't know if these have been worn down or not.




The lamination stack that makes up the coil armature is used instead of a single piece of iron to reduce eddy currents, which reduces voltage output & generates excess heat. Maybe once the small air gaps become filled up with rust and dirt it reduces the cooling ability and causes eddy currents that further reduces the coil output?