Modern Vespa

I had a 2018 Primavera used with 1000 miles that never had its valves adjusted, it ran fine, at about 2000 miles and after a ton of research, minimal tools and you tube videos I checked the valves, exhaust valves were a little loose, after adjustment it ran fine maybe slightly quieter.

Same story with a 2015 Sprint I still have, that thing ran great and quiet before and after the valve adjustment, exhaust was a tiny bit out/loose.

Also got a 2018 GTS with 4700 miles, valves have never been inspected, the Haynes manual says first valve check at 15000 miles for this era GTS 😱,
It starts on first bump every time & purrs like a hovercraft but will definitely check valves before the 15000 mile mark or if anything changes with the starting or running.

*When in doubt follow Jim C's and Greasy125's advice.

unless you suspect a problem: noise, poor performance, hard starting (cold or hot), stalling or poor fuel mileage-- follow the mfg's recommended intervals contained in the FSM.

*for bikes ridden exceptionally hard, I'd shorten the intervals considerably; preferably during another part of service, say a rear tire or trans work.

To add another data point, San Jose Vespa (south of San Francisco) also incorrectly said no valve adjustment needed at 625 miles for my 2018 Piaggio Liberty, which shares the same 150cc 3V engine with the Primavera. I ended up doing it myself and didn't find it particularly difficult. On the Liberty it's not even necessary to tilt the motor.

Does anyone know if you just loosen the rear shock bolt or remove it all together? I do not know if it is pre-compressed and will fly into my face if I remove the shock at the bottom bolt all together?

Thanks,
B

The nut is removed and the bottom of the shock is slid off the stud that remains in place. The shock is not pre-compressed, it will be at its furthest extension when on the centre-stand. Very quick and easy to do.

I agree that it's not particularly difficult but it is time consuming and patience requiring as well as the proper tools. With the Liberty there is a lot of bodywork to remove and put back.

I also have a Liberty and have written out how I adjust the valves before in this forum. Because of the difficulty in seeing the valves while you adjust them I like the imprisoned feeler gauge method.

This means you get the correct size feeler in there and adjust until you feel some tension on the gauge while you slide it back and forth a little and then tighten the keeper nut at that spot.

I also had trouble keeping the keeper nut from turning the stud in ever so slightly so quickly adjusted the feel as slightly loose before tightening the keeper or lock nut and letting the stud move with the keeper as it is tightened.

Then you try to get the next size bigger feeler gauge in after everything has been tightened. It should not go without some force or not at all and just refuse. You should be able to feel quite a bit of tension on the gauge when you move it back and forth a little if you can get next size bigger in there. Then check again for tension feel with correct size feeler gauge, it should go easily with very slight tension. You can also check a size smaller to get a feel for the resistance to very loose.

What I am describing is a touchy-feely skill that will come to you when you are doing doing it. You will be able to feel the tension and know it is just right.

And just remember the danger for engine damage especially for air cooled engines is with a valve that is too tight. If you are going to be off it is better to be a little loose than a little tight.

Well, I can't agree to this statement.
One needs to remove the center panel under the front of the seat (easy), and the cover on the CVT to turn the engine over (easy), maybe release the bottom of the rear shock.....and then you are looking at the valve cover.

O.S.

Why do you need to (maybe) release the bottom of the shock?

How do you take off just the center panel? In Robot's video he removes the panels sequentially starting from the back. the side panels come off before the center panel under seat. How do you do it (easy)?

While it may be more time consuming to remove the body panels I feel like I can do a better job when I can see and reach what I am doing.

Nice pictures, but a little vague on the written description. I tried to be pretty descriptive in how I actually did what I did at least. If you have an improvement that is great, I would love to learn it but putting easy in parenthesis is not much of an explanation?

Truth be told - if a LIBERTY valve adjustment required a bunch of panels to remove - I'd have never purchased it!
I bought the Piaggio service manual to check things out - before I decided to buy the scooter.

Why release the shock?
Because you can then tilt the engine up/down to make it easier to access the bottom fasteners. And maybe make it easier to work in there with the feeler blades? (I reach underneath for those fasteners)
Sometimes I do - sometimes I don't. Depends on how clever I'm feeling that morning....

Sorry - no intention of being flippant with how easy the front panel is to remove. Never saw robot's method. (I've read that the valve adj. on a PCX requires starting at the tail light!!)
Hope this helps.
O.S.
OK, center panel removal....
4 screws...

Thank you for the explanation OS, you are absolutely right. I went back and looked at Robot's video and the center panel is the first thing to come off. I had remembered the sequence wrong and apologize for not looking it up before I posted.

I have been very busy lately and should have done my homework before I posted. I was doing a bunch of other stuff to mine when I adjusted valves so I just went ahead and removed the panels as per Robot's video. It wasn't bad just time consuming and it does allow for better access which I think is handy especially for first time adjusting valves on the scooter.

With panels removed you can see and reach a little better but it is still difficult to see and reach.

Thank you for straightening me out and the excellent follow up post. I have yet to buy the shop manual for the Liberty. I really don't want to do the download would prefer the paper copy.