Modern Vespa

I in no way blame Scooterpartsco. for this.

I am not a metallurgist but I'd bet cash money this piston fails. I would never let this piston out of my shop. The human that stamped it should have scrapped it. Dare I say someone at Malossi thinks us mericans don't inspect the parts we buy.

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Agreed that should not have left the factory.

yeah... someone needs their butt whuped.

however, if you want to try using it I have a matching rod I can sent you.

I'll even throw in most of a wrist pin to make up for the missing big end.

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I don't understand your post. I started this thread so people know what to look for when they buy parts.

This post was not quite
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Try again, perhaps?

... I'm trying to figure out what that piston has ...
Is it a erosion? Isn't that a superficial stain?
It is strange that the seller did not notice this ...

Could have been the last cast pored. The aluminum started cooling and some air bubbles formed. When it was machined the cold area poured shows itself. that's why it's called a casting flaw.

It comes in a kitted box with everything wrapped up.

Even so, it is the seller who must replace the defective part ... Then he will contact Malossi for any compensation or replacement. I don't know how it works for you but here if you sell a defective piece then you have to replace it on seller responsability. :?
But even with the casting defect that piston was machined and whoever did it "must" have seen that there was something wrong ... or it was a total incompetent from kick in the balls.

That's what you get when you try to get 100% output/input.
Oh, wait, is that the new oil retention spheroids I have never heard of until today?

In all likelihood there's some automation in the manufacturing where the imprint and machining are all done without human eyes on. That said, yeah, quality system failure.


Thank goodness nothing like this ever happens in the automotive world.... :?
Except, of course, when it does.

contact malossi direct.
https://www.malossi.com/en/

hopefully they will do you right and replace the defective parts quickly

I worked in aluminum casting for 25 years. 380 and 383 aluminum alloy. Crazy that this left the shop. But … things get missed.

Cold flow and porosity. Often go hand in hand. I’ll bet if you x-rayed it, it would be worse on the inside.

I’d be curious what it weighed compared to a good piston. We could sometimes tell a good part from a bad part just by picking them up and feeling the weight difference.

But even with a partial processing of the grooves for the piston rings, it is noticeable that the part is defective. I don't think Malossi has such a large production volume that it can't make a QC piece by piece. I wonder what other defective parts can be put up for sale if there is such neglect.

Oh, absolutely. We had a standard procedure for startup. Depending on the tool, the first number of shots were automatically scrapped allowing the tool to come up to temperature. That helped eliminate parts like the one pictured. Some of those black spots could also be carbon or some other contamination. We used everything from anti solder paste to fish oil to lubricate the tool before the reciprocator sprayed it with die lube.

There was always a battle between quality and manufacturing as to how many shots should be thrown out. I was on the quality end. I never understood it because - being casting - the scrap went right back into the breakdown furnace. The loss was almost negligible.

Still, despite all of your systems for containment and inspection, bad parts do get through. I've seen it many times; in the interest of efficiency and productivity people are pushed to their limits and the first thing to suffer is quality.

I hope they just make good on it. Bad parts happen, but a company's response is more important.

After using Malossi parts on my BV's, I had nothing but good to say about them. Now that I'm buying parts for the Honda, they are totally screwing the pooch. I bought 4 Malossi items and the only reason all 4 haven't sucked is because I haven't installed one of them.
1) Bad piston in BBK kit.
2) CDI isn't plug and play and their instructions suck heavily.
3) Haven't installed the cam yet. Who knows what could possibly go wrong
4) Variator, having fun with such a simple task.

I decided to install the Variator today. After I installed the ramp plate sliders, the ramp plate jams in the pulley hard. I can't use the stock ramp sliders in the Malossi ramp plate. The only thing I can think of on short notice is to heat the slider posts with a heat gun. Then put the ramp plate with the sliders installed into the pulley.
I'm hoping the slider posts will expand, forcing the sliders open and when the slider posts cool they will contract. Then maybe the ramp plate will move freely.

So you no longer have faith in Malossi ...
In your place maybe me too, I'm sorry.

I just did some trouble shooting on the pulley slider posts. Checked the sliders individually. One post all 3 sliders move freely. The other 2 posts do not. The posts have a slight taper. The post that the sliders move freely measures 0.220 in. at the top and 0.235 at the best bottom measurement I can get. The other 2 posts measure 0.225 and 0.24, they do not move freely. One of the posts has a casting flaw but I don't feel any extra tightness compared to the other post that doesn't move freely.
Guess I'll try some 1000 grit sandpaper.

Maybe they need to step up their Q.C. but then the important people won't make enough money

Another porous casting from Malossi. I'm not planning to install this part. Suggestions?

contact the seller, hopefully you bought from somebody that'll honor a return for defective merchandise and send you another and then let them fight it out with malossi.

That looks more like a coating issue than a casting issue. I would want to see the piston before replacing it. Malossi will always replace new parts that are defective, so if it is a casting issue, he'll get a new one, just like the OP did.

better pic of the wrist pin area , looks like material is missing below the ring groove and potential weak spot.

Those are cold flow lines under the shot blast finish. Definitely a bad casting.

Thanks for the feedback, I have contacted the seller. Only wrinkle is that it has been over a year since the order was placed. Should have opened the box sooner, but just didn't think to do that until I was ready to begin the installation.

Assuming a replacement kit isn't in the cards, what are the chances of buying just a replacement piston? Everything else looks fine.

What kit is it? Pistons are available for them.

It's for a 2016 Sprint 150. The number on the box is 3116550.

If you do hear back from the selling dealer and they can get you sorted out, that's great.
The item has not been installed, so if you aren't able to get it replaced by your dealer, we can replace it as a warranty issue, as long as it is defective, and not just cosmetic. The black smudge on the skirt is likely cosmetic.
The piston and rings you need is part 3413216.O Malossi is out of that piston, except in the A size, which is the next size up from the O. The piston and rings are about $120.
These parts are supposed to be back in inventory late January, so if you want to replace it sooner, I can ask them to replace the cylinder too, so the piston and cylinder match, as long as everything's brand new and shows no signs that it was installed, even briefly.

Very kind of you to offer! I ordered the kit from Scooterpartsco last September. Just waiting to hear back from them.

Good luck with that.

Ha! Just figured out

Sent a message through the contact section of your website yesterday, but I'll send you a DM shortly.