MOPED ARMY

I've never been able to justify shelling out the cash for one, but if I ever had the space for an actual shop I probably would

Yeah, same, I would say that if I had to build a couple v8s with two or three rings per cylinder every year I would buy one pretty darn quick.

I have a tiny little tungsten file that I use for moped rings that is quick and precise. Even those diamond fingernail files, the higher-end ones, work pretty well.

I use a very nice Swiss jeweler's needle file (that I already had for jewelry stuff). I believe it's a #6 (173 cuts / inch).

Sure , make it a complicated ordeal . LOL

I'm taking bets that the new malossi 43 mm vespa kit which comes with the rings installed is already perfectly gapped to 0.172 mm. I'm measuring them with my main mentor at noon. I have a nasty habit of breaking then removing or installing.

If this is totally wrong ( off the moped army wiki) could you please let me know where your info comes from. I'm not saying that you're not correct I'm just asking for some validation before I go and do anything cuz I am going up in less than an hour this afternoon to get the rings gaped on this 43 kit.

43 mm = 1.69"

1.69" x .004" = .00676"

.00676" in mm = 0.172mm. For the top. The lower following what I see on the internet is .005% and thus is greater. I calculate 0.214mm.

Is this correct for a 2 ring piston ?

so the math would be

top ring:

.006” x 1.6929” = 0.0102” rounding up.

a .010” feeler gauge is used to verify here.

bottom ring;

.007” x 1.6929” = 0.0119” rounding up.

a .012” feeler gauge is used to verify here

check out the wiseco link, it has different specs for different applications that give for a better understanding of gap size vs application.

it also says don’t do smaller then .010” for a ring gap so there’s that too and i’m pretty sure wiseco makes smaller displacement pistons as well

whoops had to read it twice. the .010” minimum gap they spec is for the oil rail, which 2-strokes do not have.

still you’d end up with .076” for the top ring and .093” for the bottom ring if you use the “high performance street” specs

they also mention that having a bottom ring with a bigger gap is important to reduce ring flutter

And super thanks for everyone's help btw. As soon as I clean up the motorcycle lift I'm going to replace the kit with this one.

Exactly!!

While you are at it go check out the new polini e bike motors...completely rebuildable. All the other majors ...nyet to fixing.