Victa 70 series cleanup and rebuild.

[BradenM]

I've finally started doing something with my Victa, and seeing as there dime a dozen in AUS, I have taken the Ghetto route (sand paper to get rid of carbon buildup on piston).

Dual transfer ports (barely visible at bottom)

Piston ported simplicity.

Built to run, no frills.

Wonder whats going to happen to that aluminum flywheel when I take it to 6k rpm?

Threaded and tapered shaft requires mucho dollars for use.

Prototype mounting plate.

Exhaust port routing through base plate.

 

[Jerryburger]

Wow! Those are pretty cool engines. Thanks for sharing it's innards with us!

 

[BradenM]

Thought fellow 2 strokers would appreciate it, and for Aussies, victa is typically the first thing we think about when we want a cheap go kart motor. I will be evaluating the feesability of using them vs. other options.

 

[Jerryburger]

Too bad they're so far away from Arizona! Looks like a neat project motor!

 

[kibble]

Isn't sand paper + piston considered a no-no?

 

[Russ2251]

I would like to play with one. Problem with these engines is the parts availability. I've done general searches for them and come up with little more than crank (?) bearings.
Look into mounting engine with cylinder upright. Would be easier to mount a carb and (especially) muffler.

Wonder whats going to happen to that aluminum flywheel when I take it to 6k rpm?

Nothing. Make sure it is properly torqued if removed/replaced. Don't over speed without a load.
Questions:
Is jug cast iron?
What is importance of diaphragm hanging off of cylinder head?
What is significance 020 on piston crown? Perhaps an indication of oversize piston/rings from rebuild?

 

[Kenny_McCormic]

020 probably indicates a .020" oversized bore. Im VERY curious what the hting o nthe head is, decompression?

Your not suposed to sand pistons, there are chemicals that will strip it right off(sititng in a tray of brake cleaner works).

 

[Russ2251]

Anything with methylene chloride (paint remover ingredient) will work for removing carbon and is somewhat toxic if not handled properly.
As an aside: Methylene chloride is also good for removing potting on CDI packs to find out why they fail. Faulty SCR's are common. Combination of heat and moisture does 'em in.

 

[Kenny_McCormic]

Got to be careful with solvents, I learned the hard way cleaning a carb. Stripped all the oil out of my hands.

 

[Russ2251]

Stripped all the oil out of my hands.

It'll do more than that. Can you say necrosis?
Methylene chloride can be found in some chain lube aerosol cans. I keep it handy for instantaneously killing spiders.
Yes it's true...I had arachnophobia before the movie came to theaters.

 

[jr dragster T]

Ewww...Howcome after googling necrosis I got come REALY disturbing results?

 

[kibble]

As an aside: Methylene chloride is also good for removing potting on CDI packs to find out why they fail.

Really? What exactly does it do to the material? Dissolve it? I'm interested as I have some stuff that's potted that I'd like to remove the material from.

Got to be careful with solvents, I learned the hard way cleaning a carb. Stripped all the oil out of my hands.

But weren't you the one that said you liked to get your hands filthy with grease and oil?

Yes it's true...I had arachnophobia before the movie came to theaters.

Awww dude, I like spiders, I'll hold them with my hands! Even those huge Garden spiders you can sometimes find in the back yard. I once kept a Black Widow as a pet.

Ewww...Howcome after googling necrosis I got come REALY disturbing results?

Because Necrosis IS nasty stuff!

 

[Russ2251]

What exactly does it do to the material? Dissolve it?

Yes, but has to be done in layers as paint remover only goes so deep before it stops working. I pour enough into a coffee can to completely cover potted parts and let them soak. Time it takes to soften potting varies. I use the strongest paint remover I can find. Kleen Strip makes several different strengths.
Takes time but is worth it in the end. I use Exacto blades to peel away softened material then soak again.
If really careful, values of components (caps, transistors, diodes, etc.) can be deciphered. I've done it on a few L-B CDI packs and television flyback transformers.
It's really an old trick that I learned when I built Tesla coils (another hobby).

Awww dude, I like spiders

The top 2 biggest fears in homo sapiens is fear of snakes and then spiders. I have no problem with snakes.
I think we went off topic. Sorry.

 

[Kenny_McCormic]

But weren't you the one that said you liked to get your hands filthy with grease and oil?

I dont have a problem with it, I seem to remeber saying something along the lines of hating working on mechanical stuff with gloves.

Im rather familiar with skin rotting off. I will try and find that picture from a few years back, bad skin infection.

 

[jr dragster T]

Is it a picture of yourself kenny?

 

[BradenM]

Ok;
The diaphragm thing is a mechanical compression release. the 020 on the piston denotes part number AFAIK. The head hasn't been pulled of that motor ever, There is absolutely no reason to re-bore and fit an oversized piston and rings to a Victa; it would have been cheaper to buy new.

Sandpaper and pistons ARE a NO-NO. Victa's are dime a dozen in Australia; If I kill this I'll get another one. Keep in mind, these things were built to run, thats it, no frills. Nothing fancy whatsoever; about as innovative as these things got were the tapered and threaded shaft. The guy that invented these used a peach tin for a fuel tank-this is the root of the company.

I agree, it's much easier to mount it vertically, but I'm looking to make something individual and it will serve my purposes better this way.

When you say "jug" I am assuming you mean the block. Yes, it's cast iron.

FYI, I will suss out the cost of shipping a victa motor to the US for those interested, if you really want one.

 

[Kenny_McCormic]

Is it a picture of yourself kenny?

Yes

 

[kibble]

FYI, I will suss out the cost of shipping a victa motor to the US for those interested, if you really want one.

Whoa! Really? But what does "suss out" mean? That you'll ship one out if we pay the shipping?

 

[robin]

as it is a 2 stroke can you do some porting work for ir and make an expansion chamber exhaust and if you don't mind measuring what is the bore x stroke ?

 

[Russ2251]

do some porting work for ir and make an expansion chamber exhaust

Probably won't stay together.