OK wombatini hi and welcome sounds a bit like these two mowers have had some time spent together and somebody with a bit of mechanical knowledge.Yes as Blue said if a moderator could move these posts into a new topic that would be much appreciated as this is more focused on a restoration topic.
However I will help where I can.The series 70's mark I engine didn't have a decompressor and had the Impulse starter.As without the decompressor the engine can kick back with a zip starter,and believe me that does hurt when that happens.So you are correct there.
It does happen from time to time people like to swap parts over to keep there old girls going.I picked up a VC-160 Auto drive MK II that some somebody had changed it to a G4 carby snorkel.Fortunately for me they didn't change the hose.
Like this it was.
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Unfortunately for you I don't have nearly enough of my own so I can't spear one for you.You will find that a lot of the air tubes off other models will fit.Like a VC-Sports and VC-125's are the same hose.Really not sure if new ones are available.If they are hey please let me know as I do need a few.
OK sounds like you may have a VC-160 Mark I and a VC-160 Mark III.The Mark I should have been a Vicatcode V80 being produced from 1970-71 engine number should start with 5270 or 5271 depending on year made.G3 carby alloy fuel bowl and an Impulse starter.Should have looked a little like this.
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Your second mower sounds like a VC-160 Mark III from 1972-73 engine number would be 5272 or 5273 depending of year made.Victacode indeed is V111 G3 carby.It could have either had a alloy or plastic fuel bowl as Victa were changing to the plastic fuel bowl around that time.
My Mark III came with a alloy so I just left it on there.They have the Zip Starter on them.
Here is a picture of a N.O.S mower from 1972 with the plastic fuel bowl.
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and mine one with the alloy bowl both correct for this model.
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The only other different's is some of the Mark III's had the casting on the bottom for the auto drive belt.Most didn't have it but some did.Here's mine that does.
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Generally they look a bit like this.
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As far as the work your doing on the engine,as I restore each mower I always go for the standard size bore.If I'm doing an engine and find an over-sized piston and bore I always put that aside and use a standard bore.I guess because I want them as close to factory as I can,and also I guess because once you start going down the oversize road you do start to run into a lot of cost,and I mean yes we love them,but how much do you really want to spend on them?
So if it were me I'd keep it standard.
How bad is the cylinder?
As far as spare parts go,I'm sorry I moved a couple of years ago and I had heaps of spares as I'd pulled apart close to 20 before the move.Some how I've manage to lose most of those parts and are having troubles locating bits I need.
Just keep and eye on eBay they are always popping up there.
Also ask Bruce I know he used to have air cleaners,hoses and throttle housing,but I'm not sure now.It's been a while since I looked in the spare parts section.
I know this has been a long post but I hope it helps.
Also stick some pictures up it always helps us out.
Anymore problems just ask away always happy to help.
Take care all.
Happy new year,and happy mowing.





Here for a good time,not a long time.