OutdoorKing Repair Forum Forums Restoring, Customising and Modifying Victa Walk-Behind Rotary Mowers 1971 Self Propelled

I say spray the edges with plenty of WD40, forget it for 7 days and hit it with a block of wood and observe carefully if it has moved.
Even better would be an air hammer that I have used to do stuff a hand one couldn't.
It uses powerful pulses instead of brute force and has gotten me out of trouble before ( not for this though).

Yes exactly I'm very much the same way,but if you have to re-bore to save the cylinder (of which I highly doubt it is very very rusty)Re-boring mean that's it not the same as it was from the factory.If I'm restoring a engine and find that is has been re-bored.I straight away take it off and put a standard bore on it.As re-bored cylinders are not original.
In your case you will be lucky if you can even get it apart and what then? Nothing will be usable and you would have wasted so much time in getting it apart.I'd just start looking for a new cylinder.Will save you time and at the end of the job you will still be just as happy.As you will have saved something that was dead.

What I do is to get the two nuts on the thread tighten them together by turning them the opposite way to each other,then I have a spanner on the bottom nut and undo the stud.If you take the studs off you will be able to get the crankcase apart.I'm guessing you'll see more problems in trying to get the piston out.I feel that trying is only taking up time for you to see that there will be nothing savable.Cylinders,pistons and cranks really aren't that hard to find.

Well for a start, what are you using as penetrating oil? I'm not at all a fan of WD-40 for this - it's not at all good in this application, and wasn't designed for it.

Acetone and Auto Transmission Fluid mixed at 1:1 v/v is better than most commercial products; and as a last resort, brake fluid can sometimes save the day.

Yes, the barrel should just slide off the studs.

With very badly rusted studs, they may be rust-bound where they pass through the cylinder fins, as well as at the crankcase.
If it were my engine, I'd be thinking about using a 1mm thick cutting disc, to cut the studs a little above the cylinder base. As well as a 100mm angle grinder, I have a 3" pneumatic 'exhaust pipe cutter' which is very handy for such tasks.

Thanks for all the input guys - I'm learning lots from you all.

While I still haven't got the thing apart, I have had a couple of small wins.

1: The piston is budging, I've moved it about 5mm down the bore - so things are slowly breaking free. I am being as "gentle" as I can, while wacking it with a block of wood. Still giving it time and lots of penetrating oil.

2: I have managed to get another stud out - unfortunately the two left in are on opposite sides of the crankcase - so I still can't split that - but it appears time, patience and perseverance is winning. I really don't want to start cutting studs and things. I would really like to keep as many of the original parts as I can. Its not time - I don't care how long a restoration takes me - its not the money - studs could only be a couple of bucks - its just that when its all done, I can look at it and get some kind of weird pleasure in thinking that all those parts that were put together in the factory all those years ago and back together and functioning well - hey - I know I'm weird....

As per your advice - I have checked the studs where they travel through the fins to ensure they are not rusted to the fins - they are free - they just seem to have a very good hold onto the crankcase. Time and lube (I will make up some Acetone and Transmission Fluid and try that as well) should help. I can actually turn the crank shaft a little bit now, and I can see the barrel moving up and down the studs, with the piston still fixed in the bore.

2: I tested the coil - and it works!!! I know that doesn't guarantee it will work under load, but its a good start

At the moment I am amusing myself with little jobs, cleaning parts etc, while the barrel/piston is soaking in a bucket of diesel.

Hasten slowly Grasshopper!

Polybus

I'm not sure you read my post.This I have found is the best quickest and easiest way of taking the the bolts out.See below and my post above.

G'day all

The main thing is to preserve the crankcase numbers.
The fact that the cylinder has moved 5mm is equivocal -
is it a result of the crankshaft turning to reach TDC;
or has the piston genuinely moved in the bore?

Blumbly's 'two-nut' approach is the conventional method
for removing studs - but that may not be the best option here,
given the objective of saving the crankcase and the extra-long
length of the studs (torsional issues); and the severe corrosion.

Stud extractor tools are used commonly if the 'two-nut' approach
doesn't work.

My best advice is the un-seizing of the piston-to-cylinder.
Both Gadge and Norm have expressed the view of timely chemical
treatment.

It may be that holding the engine cylinder in one hand and tapping
down with a hammer handle on the piston head will do the trick.

This seems to be a multi-strategy approach, and I feel all contributors
have given good advice; but the most gentle must be the chemical and
wait-and-see approach.

After your long sojourn, we may have to call Chuck Norris.

----------------------
Jack

Let's stick with David Carradine for the moment.

Blumby - yes I did use your advice - sorry I should have mentioned it - I tried the two nut approach - and it worked really well as far a getting a good solid grip on the stud was concerned - it gripped it really solidly. In fact it gripped so solidly it got to the point where I felt the torsional force I was applying to the stud was just about sufficient to snap it - hence I gave up and decided to apply more lubrication and more time. But the two nut trick worked really well - as well as my Stud Extractors anyway.

The piston really has moved in the bore - it is only a small amount, but I can definitely see more of the ports, so it has genuinely moved in the bore a small amount.

I agree - I have received excellent advice for everyone - and I will continue using everyone's advice - lubrication, time, judicious use of mallet and wood, and patience.

As I said previously, I will need to head out of Sydney for 6 months in 5 weeks time - and if necessary, I am quite prepared to leave it soaking for the 6 months I am away.

Polybus

OK it does sound like to much waiting for parts that may not be savable but you do need to save the crankcase as you need the numbers as it was the original engine.
Aside from that what is it do that you have to leave home for 6 months? Sorry just curious.

There is a fast [destructive] chemical way to remove the piston, without any damage to the bore. These solutions will attack rust, but not iron/steel.

But it does require some access to the underside, so as to part fill the inverted piston with the alkaline chemical solution. 5mm would be sufficient, if a syringe and plastic tubing is used.

Inverted - so that when the piston crown is eaten through, the solution can run out into a catch tray, not into the crankcase!

The 'mild' approach is to use Trisodium Phosphate, available from hardware/paint shops as 'Tricleanium'. Say at 5% w/v; 5 grams per 100 mL of water.

BTW, half that concentration, i.e. 25 g/L, works well for cleaning range hood filters, but keep a close eye on them - it works rapidly on those.

Whereas the 'aggressive' approach is to use a Caustic Soda [Sodium Hydroxide] solution. I'd try this @ 5%, too. Add the soda pellets to cold water.

Safety: face/eye protection and rubber gloves are strongly advised, when preparing/using these chemicals.

Blumby - I'm heading off to Mildura for work for six months - I work in the public health system so I move around to a lot of different hospitals.

I get around quite a bit, and essentially I've been away from home for 10 years.

2007-2010 - Gold Coast
2011 - Sunshine Coast
2012 - Cairns
2013 - Mount Isa
2014 - Bundaberg - Hervey Bay and Maryborough
2015 - Port Douglas
2016 - Mildura
2017 - First 6 months home in Baulkham Hills - second six months Mildura.

And I've had that long without any of my tools or a workshop - its been terrible not having access to my toys.

But hopefully come February next year, there will be big changes - no more than about 4 weeks away at a time - hopefully.

Either that or time to change jobs.

Polybus

Why do they require you to uproot where they could simply hire another person that lives locally??
Not exactly family friendly.

Hired gun. Sometimes it's necessary to have an outsider in, to run a 'cold eyes review' program, and cut away the cruft that accumulates over time, in any organisation.
No.
But they're not alone in that - look at Oil & Gas industry offshore rotation rosters, particularly expat ones, as a prime example.
Most of those who work these jobs plan to do so only for a limited time, purely for the money - to accumulate significant capital that would take decades to build up, in a 'normal' job.

No nothing like that - I'm a doctor and they are terribly short of doctors in the bush. I like to go where I can do the most good - so I go bush - where-ever I can do good.

But onto more important matters.....

Progress with the Self Propelled - and more questions.

I have managed to get another stud out, meaning I have now got three out - so there is nothing stopping me (as far as I know) splitting the crank cases - so that is my next task.





I had given the cases a wollop with a rubber mallet, and I think I have broken the seal between the cases, I can see movement there when I move them by hand.

I can also see movement between the barrel and the crankcases, so that is fgreed up.

The piston, while it has moved a small amount, is still quite stuck in the bore.

So....

Where do I go from here? How do I get the crankcases apart? In the Victa manual I have it says whack one end of the crankshaft with a soft mallet - I've done that, but not a lot happened.

Am I being too gentle??

Polybus

Ahh; well bloody good on you, mate!

Always better to start gentle and ramp up as necessary, I feel. It's the bottom crankcase half that has to come off first here, as the remaining stud is in the top half. BTW, the points cam is a slip fit on the shaft, unless it too is rust-bound, so it needs to come off too.

First you need to get the blade disc boss off the shaft, and there's a bit of a trick to that. It's held on by matching tapers, i.e. male on the shaft and female in the boss.

Removal procedure is described in this past thread: https://www.outdoorking-forum.com.au/forum/ubbthreads.php?ubb=showflat&Number=53044

The crankshaft pulley is on a parallel shaft section, keyed with a woodruff key. It may need a puller to get it off; if so the 'bearing puller' type is the best one to use here.

The workshop manual procedure is:

Which Victa manual do you have? Of my collection, Gregory's #103 has good coverage of the pre-1972 SP, but #424 is better.

You're making encouraging progress there. Good on you for helping in the bush's shortage of doctors. Looks like you are giving up a lot to do it so that makes for more kudos points.
This must make for a therapeutic hobby for you.

Right - went out and bought a couple of three armed pullers - I've been meaning to for ages - so this was the perfect reason for doing so. I've wished I had some on a number of occassions while working on my Stationary Engines.

Good/The right tools always make life so much easier, and less expensive in the end because I break less things

So now with my new pullers - Blade Boss and Pulley are off

Shall wait till tomorrow to see if that has helped me much or not.

Not entirely sure which version of the manual I have - I got it as a PDFand it doesn't have the cover pages.

Polybus

What sort of puller did you use successfully on the blade boss? I have a 125 that the two hammer method has failed to budge off and I really hate employing that method. Terrified already that my attempts so far have bent the crank shaft.

This is the one I used.

SuperCheap Auto - $50 - yes - its a hole in the pocket - but it worked for me.

http://www.supercheapauto.com.au/Product/ToolPro-Gear-Puller-3-Jaw-100mm/12540

As with everything I do - bathe the thing in (your favourite brand of) penetrating oil and give it time....ideally overnight.

Today I was just lucky - bathed it in penetrating oil - applied the puller, tensioned it up quite tight and when I went back about 3 hour later - applied more tension and it came straight off.

Sweet

Polybus