Modern Vespa

So I ordered a stud for the exhaust because there was only one. And I found some like glue substance covering the hole. Once I opened the hole I found that the stud doesn't fit? Did I buy the wrong stud or is something wrong with the thread? The same nut fits both the new stud and the stud that was already in there. So im confused.

Looks like the original snapped off. You're going to have to lay it on the side, drill it and use an easy out. Put some good penetrating oil on, and let it set over night. Harbor Freight has a good set of extractors with left hand drill bits.

Are you sure? I don't see anything inside of it and I can fit smaller things in and all the way through it. It's just that the bolt seems tiny compared to the threads.

That looks to me like it was stripped out. Especially since it was plugged up with some glue?!

I wonder if something like a Helicoil might work here. Or maybe a new cylinder is needed.

Yep, Sorry. I didn't catch the scope of your problem. Can you get a tap in there and go up in size slightly? Where has Greasy gone? He will steer you straight.

I'd buy a TimeSert kit to bring it back to stock size. You can purchase a kit that includes the correct size drill bit, a tap, a TimeSert insert, and the tool to install it. Lots of YouTube videos showing how to do it.

edit

Are you sure the glue wasnt some kind of liquid gasket sealer someone put on the gasket?

Did you compare the new stud to the old installed stud? Same diameter? Same pitch? My local Ace hardware store has an assortment of metric studs that I've used successfully. Got something similar near you?

Thank you guys so much for the replies. I'm going to have to go the timeSert/helicoil route and see what I can do. The seller of this bike said it's up to 98cc so I'd rather not have to replace anything because i don't really know what he did to it. I have no clue, it was completely black and all gumped up. There's no signs of it anywhere else on the bike. And yes the studs are the same.

being its a 2 stroke I would remove the head and cylinder take it to a machine shop and have them do a repair on the exhaust flange versus a insert.

that cylinder does not look oem to me so it very well could be a big aftermarket replacement.

also by taking the cylinder off it would give you chance to sand blast it and put some high temp paint on it.

Just grab a second hand one from Fleabay or a breakers yard, cheaper than messing around or buying tools.

Another option, tap the hole next size up and use a step stud.

https://belmetric.com/studs/metric-step-studs/