Help needed re correct sizing of rear hub oil seal PX125e

[oldscabby]

Hi I’m am new to this forum but have had a Vespa for about 16 years now A 1989 Vespa PX125 with a polini 177 barrel and piston but that isn’t the problem that runs fine. My issue is with my spare engine (prefix No. VNX1M)which I believe to be a PX125e circa 1983. It been in a crate for many years Although it had just been rebuilt when I bought about 15 years ago. This year I decided to get I running again. I replaced all the gaskets ,rubbers an obvious seals as well as a carb overhaul . I went to top it up with fresh oil today only to find a big puddle under the rear drum. My first thought was failed rear hub oil seal or wrong size fitted by whoever rebuilt it; the one I pulled was a 30 x 47 x 6 but this seemed a bit loose around the drive shaft I measured the shaft best I could without a vernier gauge and thought it to be 27mm diameter hence the oil leek I replaced it with a Corteco 27 x 47 x 6 which I took fresh from a packet in my spares box and that also leaked but not nearly as much. Is there a way I can be certain what seal size is correct for my engine by measuring up an if so what/where exactly should I be measuring?

thanks in advance for any assistance

[mijapxman]

If your engine is using its original size 27mm hub, the 27mm seal is the correct one.

Sometimes, people fit a 30mm seal rear hub and 30mm seal.

Measure the outside diameter of the inside part of the hub, that slides into the seal, it has splines that match the wheel shaft on it's inside.




Check here, under bearings and seals...

www.wasp-performance.co.uk/p125x-1977-1982.html

Mij ☺

[ironsloth]

Use wasp or any other scooter firm for seals, but if you go through a few (as in building other scoots for people etc) speak to these guys:-

www.fairwayseals.co.uk

This means you Mij...