Modern Vespa

Hello fellow Vespa riders
I am getting ready to get my vespa out of hibernation from this long NH winter.
Vespa been inside and on a trickle charger since November, checking everything ... and find this sweating pipe cover with oil....no clue what is causing this issue...or is just normal?
2013 gts300ie with13.300 ML also trying to change the gears oil but no one have a 80W-90 gl4 n only gl5 is that ok?
any help or suggestions will be greatly appreciated.

That pipe being oily is normal, and GL5 is fine. The interwebs rumours of GL5 not liking certain metal compounds are 30 years out of date, pure FUD.

Thank you so much... for the reassuring tip you are the best

That part is the crankcase breather valve, as long as I know it, and I have trouble understanding whether it can be just a free air pass into the space under the cylinder head or whether it shall have some diaphragm assembly? My OEM parts catalogue shows a diaphragm assembly, while my Leader 125 cc has just an empty housing and free air pass, so I can breathe freely through it having that hose in my mouth while the oil sump cap is off. I wonder whether the absence of a diaphragm may cause engine overheating? Thank you if anyone takes time to read this.

Might be the crap hose clamp, those things suck in general, more so on a small diameter hose. If not replacing it with the factory Oetiker, spring clamp would be better.

I include on my silicone products Breeze aerospace lined clamps in stainless steel.

I will duplicating all of the coolant hoses on a 2025 GTS 310 , the breather hose will be lined with Flurosilicone to last forever.

I have plenty of time as the new frame assys will be custom two stage no water based paint in Arizona.

The plastic assembly shown could be cnc machine in alloy , but most dont keep there scoots so long .

The last complete I did was 2013 gts300

Below is some of my work for a group of Chevy SSR owners.

GB

This is off topic, but well within aerospace - does anyone use moisture control membrane to cover longeron openings on LX bodies? GTS possibly has those holes too, which collect dust and debris, and through which water may get into the longeron from the engine washing hose. Thinking to cover them with a breathing membrane to prevent all these things.