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

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

It may still be possible to work out which version it is, if it's one of the Gregory's publications.
https://www.outdoorking-forum.com.au/forum/ubbthreads.php/topics/81688/