OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Victa Two Stroke Engines Victa 160 disassembly

Thats not good at all - I would say a good 8/10 bad

Rings look seized in the piston - and scoring is pretty bad.

As Norm advised, I would first pull the head, pull cylinder barrel (check), rip piston off, soak in penetrating oil to help remove the rings then very gingerly remove them. Clean up piston and ring grooves, check ring gap in bore

Seeing that through the port, I would personally hone the bore and put a set of rings in minimum (possibly piston as well) but the problem is you are a long way from the parts bin

Oh dear, I think we have found the reason. That looks a solid 10 in my books. Nasty.
Dismantling is inevitable. It takes just one ignoramus to mess it up.
Time for the fun to begin.

Hi Both,

I think I could wiggle the rings a bit with my fingers. So not seized.

Haven't really spent and money yet apart from an air filter so not worried about throwing money down the drain yet.

So, worst case, new piston and rings? Possibly some cylinder bore honing?

Before I strip it apart, what other things might I have to replace?
I presume the head gasket at least?

Can I get the piston out by moving the cylinder as would probably be easier than taking the crank case apart? (Think that's what T was suggesting)
If I can i would need the base gasket?

Are the gaskets special? Can I use stock cardboard gasket material?

There are a few pistons and rings up for sale here so might be OK finding one.

Thanks again

Hi Chris

Undo the 4 head nuts (circled), then take head off.

Then pull on the barrel, it will separate in location I have marked (the studs are screwed into crank case so wont move)

you will be left with the 'crankcase' with a conrod an piston sticking out

Easier to get the lower g clip (which locates gudgeon pin) off the piston with motor off the deck, but is achievable with it on


You need - head gasket, base gasket (can make base gasket from gasket paper but not head gasket)


Don't buy anything till you get the barrel off - as if that is deeply gouged you need a rebore, oversize piston

Thanks T,

Pulled apart as pictures.
Exhaust side looks pretty bad. Think the cylinder may be OK
Although does have a bit of scoring.

You were right, one of the rings does seem to be jammed in on the exhaust side but they feel springy otherwise.

Getting the lower gudgeon clip out is going to be tricky, missing angled long nose pliers but I have an angled circlip remover so will try that.

Of course, I was forgetting it's only around 4pm over there - I was thinking 'gee, he must be awake and alert to do that past midnight' then remembered the time difference

They will latch in on the exhaust side after straight fueling. You can try very carefully getting them out with a good soaking in penetrene before attempting removal

Don't try to stick a flat blade under the ring, try to use your hands to push the springiness to the seized spot to try to pop it on its own if that makes sense. a little light help of screwdriver is alright, but don't go twisting hard

And to answer what might be your next question, there is little chance of bottom end bearing damage - they are tough old things. Plus, yours should have the needle roller little end (as opposed plain to sintered brass) so thats fine as well.


I would also start soaking the blade plate nut in oil in preparation just incase you have issues with the gudgeon

Regards

Just saw photos as didn't come up before

Not liking the piston - free up rings and clean piston with sand paper and it will run - might be gutless and smoky though

Bore looks alright with a hone, hard to tell when I can't feel the scores though

I am not liking what looks to be rust on the crankshaft counterweights though - could be nothing but worth checking bearings arent grumbly. Not impossible to do bearings on one of these, just getting a bit involved

By the way re the missing angled pliers - that why I bought 2 pairs as they come in handy haha

Regards

Thanks, do you know the part number for the piston?
Do I need to think about oversized pistons and rings?

Think I'm heading down the road of a complete engine rebuild. The bearings don't feel as smooth as they should be but not terrible.

Machine has been left in a damp environment for a long time so although it wasn't too wet obviously some moisture has got in there.

Getting this running might keep me out of trouble for a while yet.

Got the blade disk off already, must have known it was going to go that way!

In sequential order:

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Oversize - not unless you want to rebore

Rebuild - No, top end only most likely. But with bearings its all relative - I just tore down a later model with bearings which felt average, but would knock over 1/2 throttle. I would suggest squirting a fair bit of thin oil in them, swish around and then tip back out to check the colour. If brown crusty gunk comes out, you have a problem.

You were very lucky regarding blade plate - last week I (110+kg) was swinging on a 600mm breaker bar + another 300mm of victa handle and even with my heavy frame it wouldn't come off with heat or soaking in penetrene. The blade carrier looked like a pretzel by the time it came off.

And that was 10 year new model than yours

Tyler, you obviously need a good rattle gun, makes it so easy

G'day SR,
Can't find the UK Victa parts seller I've recommended before via Google - will have to run a search on my old ODK posts.

There is this mob, but it's not clear what bits they might have for the older models. http://www.victaspares.co.uk/

The head gasket is made from a special material; the later PowerTorque 160cc head gasket will fit, IIRC.

The base gasket is nothing special; gasket paper, or even cereal packet cardboard, will work just fine.


Tyler, the 'poppet valve' we refer to here, is the one in the deco valve, not the one used in the G4/LM carby.

Yep, these nuts often only respond to impact.
Which can also be applied by using a long ring spanner and a 2lb hammer, as we had to do in the old days...

Hi Norm

Tried Rattle, nothing doing. I think I need an air impact one day

Gadge, understood - usually think carby when hear poppet and victa in same sentence haha

Hi Tyler,
when I said rattle I meant air impact mine is a 1050nm and it has never let me down on a crank nut or bolt. My old 320nm just wouldn't cut the mustard on the Victa nuts. Only downside is with the big one is you can destroy sockets easily

Hi Norm

I have only ever used anything up to 340 ish, so that makes sense. My regular one doesn't normally have significant issues, but sometimes just won't touch it

Hi Gadge,

Thanks, that helps a lot.
Think I can get hold of a new piston and rings fairly easy but the gasket was illuding me so good to know I can use a powertorque one.

Took the piston off as picture and gave it a bit of a clean but presume that this is too far gone?

Bit confused what the shim is and why it's there, was underneath one of the rings. Is this normal?

Problem seems to have been at least partially caused by coking round the exhaust port.

Now looking at honing tools, and excuse to buy new tools.
What kind of grit do you use and presume it just needs a light going over to avoid oversizing it.

Also, what size are the engine nuts? Might as well take the engine off the body, will be easier and can give it a good clean.

Made some progress today, cleaned up head and cylinder ready to reassemble.

An impact gun would have been nice but working with limited set of tools although this has now expanded to some long angled needle nose pliers!


Thanks

G'day SR,
Yup, that one's 'had the Richard'. The Powertorque piston kits fit the earlier full-crank motors like yours, but not vice versa.
Yes; it's an 'expander ring'; which is no longer used, due to improvements in piston ring technology since the 1970s.
If you can find a local motorcycle workshop, chances are they'll have [or can refer you to someone who does] a suitable cylinder hone for this job. Good hones aren't cheap!
These nuts are [as are all on that mower] Imperial AF/SAE system fractional inch sizes.
For sure; but none of this advanced technology was available, back in the early days of Victa mowers.

Hi all.
I thought it was the other way Gadge, not backwards compatible. Rings a bell now I think about it.

Nice to see a good old back to basics Victa 160 repair refresher thread. A lot to learn /be reminded from here.

Hi Gadge,
A few years ago I was rebuilding a 1948 350 Enfield motor and somebody had fitted a Toyota piston to it, was all good till they tried to rotate the crank and the piston skirt came down and hit the crank. Believe it or not, instead of removing the piston to shorten it they cut the skirts back on each side with a hacksaw insitu. How did I know they used a hacksaw, the cuts were how it ended up cutting and I could see the teeth marks and I would say it was an 18 tpi blade. The motor was running because we went on several club rides before it gave up the ghost. Moral of the story is sometimes you can get away with murder regarding pistons

Think I can get a new piston and rings on ebay and victa spares has the powertorque head gasket.

Trying to keep cost low so any advice around honing at home welcome. Don't really want to pay labour charge for someone else to do it.

I guessed they were imperial but only have limited imperial sockets. Guessing its 5/8in as 15mm too small and 17mm too big.

Lots of questions I know..

G'day SR,

For the parts you need, it would be worth searching for 'Victa' in this FleaBay UK section; https://www.ebay.co.uk/b/Lawn-Mower-Parts-Accessories/82248/

As far as the crankshaft bearing condition is concerned, the critical bearing is the 'big end' rollers in the connecting rod. The crankshaft main bearings are standard radial ball types, and quite easily replaced. Not so with the big end.

From memory I paid $25 for my hone, always hard to justify if you are only ever going to use it once though

G'day Norm,
That's for sure! A well known expedient during WW2, when replacement motorbike/stationary engine pistons just weren't available, was to make a new piston out of hardwood - apparently red gum was the best timber...

Here's a vid of a Briggs running - with an Oak piston crown installed!

Hone tools seem to be cheap compared to paying for it to be done by someone else. Plus, would much rather learn a new skill and have the satisfaction of doing it myself. What kind of hone tool do you have NK? A ball hone or a 3 pronged one? Do you do it wet or dry? What grit?

Morning Shedrummager,
I'd use that piston, as compression comes from the rings and bore.I collected rings from old PTs and other Victas and swap them , long as they are not worn so thin.....
cheers
speedy.

Hi SR,
I use a 3 leg hone with 100mm long stones because you have to travel over the transfer ports and 100mm does it easily. Grit not sure, either 220 or 180, whatever was the cheapest on ebay at the time. I use oil on the stones and give it a good clean especially in the transfer ports one I have finished honing it.

Thanks speedy, gives me hope that the block is not completely unsalvageable!

Thanks NK, good to reaffirm what I've been looking at. Think the longer stones required to stop the snagging on the ports.

Have taken the crankcase off the body to give it a proper clean.
Rust on the cranks looks worse than previously observed. Will concentrate on getting that to a reasonable state before getting into honing/replacement parts.

Thanks to all who have replied to my constant questions, it's been a great help! I am quietly optimistic that this will turn into a fair runner but will take some time.

Deck looks in good condition at least

Lets hope the bearings aren't stuffed

What's the progress with this old girl

Sorry for not posting..
She's getting better (I hope).
Decided the right thing to do was strip the bottom end and see how bad the rust on the cranks was.
It was not good but buffed them with a wire wheel to get the loose stuff off, washed throughly now partially reassembled.

Got a honing tool and gave that a go, got the glaze off, not perfected the cross hatching but I think it'll be good.

Bearings were good, seals too. Reassembled with 2 stroke oil and crank seems smooth.

Gave blower housing a bit of wire wheel treatment and just painted it with rust converter for now.

Made new base gasket and now waiting for delivery of piston, rings and head gasket for final assembly, depending on the postman, maybe this weekend it'll be back together..

Picture of crank is before rust removal, looks bad but it's mostly surface rust.

You've been a busy bee. Progress looks very encouraging.
Wish I had table space like that. I can make some if I an determined enough.
That looks on track to becoming operational real soon.