Modern Vespa

I've tried searching but haven't really found any information on what kind of lifespan one can expect from case seals either from a miles or time frame of reference. I know that the seal quality is also a factor, so let's assume high quality seals and some ethanol blended fuel. Any thoughts?

With today's fuel? I'll assume it is a daily driver with at least 3 miles per day (urban commuter). Probably 3-5 years.

If it is a Lambretta likely longer as MB makes some trick Viton seals.

It's not a Lambretta, rather a Rally 200. I have over 6K miles on the seals in just under two years. I'm trying to forecast the expected remaining life, keeping the adage "if it ain't broke, don't fix it" in mind.

Please don't take this the wrong way, but do you also worry a bird might poop on your nose as you are walking down the street?

dependin on the pounding about 5nims ... the smaller the club the longer they last

ohh sorry maybe i should read the question as well as the title

Classic rider, Its a fair broad question, that could lead to some interesting discussion. there are so many variables that could be involved. ive heard of some seals sitting in px's that have only lasted 6 weeks, but it may have been how the mechanic installed them as well. Some seals have lasted in a scoot 30 years and still been servicable. one of my scoots has 30 000 k's on it and im not worried about changing them out as yet.

Not at all. I usually am wearing a billed cap, so unless the bird was adept at sling bombing my nose would be safe.

I have some extending riding I'm thinking about doing but at the moment am physically unable to do the mechanical work to replace the seals. I'm trying to get a feel for how long seals last since they are not covered in recommended service intervals.

Hahaha!

My vespa mechanic always insisted on me putting original brand name seals. The last time that I had my engine rebuilt due to a piston whole and glitter inside the engine I went ahead and changed the seals(my mechanic did).

Long history short, I had a freak accident in which the clutch side main rubber seal actually disintegrated and the metal ring ended up stuck on the whole of my rotary pad, I just can't think of any more bizarre way to have a seal breaking and physically locking/preventing your engine from even cranking it.

With that being said , I believe that it can go /last a few years as long as you routinely start the engine and give the engine regular use so that they don't crack.