Modern Vespa

Cant figure out what goes in here?!

I've just put back the cases together on the Rally overhaul (8 bolts present) and noticed this hole. Im convinced there was nothing in there when I disassembled it.

If this is completely obvious please feel free to abuse my incompetence

I'd have a look on the exploded parts diagrams on the Vespaspares or SIP web sites and see if anything's there as a listed part. Should put your mind at rest!

are all 4 case bolts in ?

there can be holes that are not all the time used

if it is threaded then it is a stator plate screw securing point
if you can see all the way threw it then it could be a case bolt

Yes...all four case bolts are in, in that particular area...

It does appear to be a case bolt because it goes into a blind hole (will check if its threaded, ive just run out of bolts!)

Its an odd one because this version from SIP just hasnt got it there.

http://www.sip-scootershop.com/en/products/crankcases+piaggio+for+vespa+_43352000

Its not a stator plate hole though because those three are raised and this hole sits at the back

it's vestigial, kind of like an appendix.

Pre-P 125/150 engines, of witch the Rally was basically evolved from had that top case bolt in a different position. it was moved to accommodate the longer rotary pad cutout on the 200's and the P's.

there's other vestigial bits on later cases from earlier features; the side transfers on 200's are another example.

Excellent...thanks Rob.

I'll ignore it and it should work fine...much like my appendix
Kevin

Well done Rob, I just learnt a new word I can drop into the occasional Vespa conversation...

Vestigial - 'forming a very small remnant of something that was once greater or more noticeable'

Every day's a learning day...and you can sleep soundly too now Kev

Thumbs up for Rob.. for constantly sharing his wealth of knowledge on this stuff.

it's only early P cases that have it- later revision molds didn't incorporate that bit.

funny enough, pre-P cases have a vestigial lump in roughly the same area as the later stud, even to the extent of having a hole in the gasket there. That's a vestige of an alignment pin used on VNAs to align the case halfs, like the pin down by the oil drain hole in the bottom of the case.

later cases went to using a raised lip around the crankshaft hole and the upper alignment pin was omitted. bah. no problem. you'd be shocked the shit i've got floating around in my head about these things.

Just to throw it out there- i hope some out there pay the favor back- i'm close to launching a full online ordering website to branch out in the mail order side of my business. it'll be an automated way to special order pretty much anything SIP carries.

That gets a thumbs up.

Rob is good folk! He's helped me so much already.