4.5 hr valve check!

[Stig / Major Tom]

A year since I checked the valves -

Today, I did every kind of thing a guy could do to make this a real dog's breakfast.
Dropped tools, forgot where I laid tools, lost a 13mm socket for 20 mins, put wrong screws in the panels, mislaid my feeler gauges, dropped a panel nut in the garbage disposal, tool was always on the opposite side of scoot when I needed it, flash light died, got a Charlie-horse at the 2 hr mark, got lectured by a teenaged girl ("do you really have to wash scooter parts in the kitchen sink?!" ), let my coffee get cold - twice!.....

The good: A) O'Reilley's overnighted my new Iridium, as promised! (I'm in there doing the valves - so, spun in a new one)


Drop from the shock mount to raise the engine (#4 cover bolt is tough to reach) Not absolutely necessary unless you've EasterHam sized hands, like mine.


Remove small cover to use CVT nut to spin engine to TDC


Remove bucket and front cover...




Rotate to TDC. Piaggio gives you nice marks.


Hoses & nuts make it hard to get blades in there! 0.10mm


New plug.



And it still worked!


It is not really hard on this Liberty - but I'm in to the valves in about 20 mins on my Kymco!

Stig

[CROSSBOLT]

One of those days, huh? Like the roller cam and followers! Two exhaust or two intake valves? Seems like Kymco has a better handle on maintenance access. Was that an OLD iridium plug with the pointed center electrode? Good pictures as always.

[Stig / Major Tom]

One of those days, huh? Like the roller cam and followers! Two exhaust or two intake valves? Seems like Kymco has a better handle on maintenance access. Was that an OLD iridium plug with the pointed center electrode? Good pictures as always.

Two intakes, one exhaust. (must be bigger valve, yes? will check the specs in serv. manual)
Not going to admit if the old plug was an Iridium - would get mean mail for changing it after only 4,000 miles.
Next is a belt & roller change at 6,000 miles.....with oils changed in there somewhere. $32 for the belt - so no worries about these freq changes per the Piaggio schedule.
Stig

Stig

[CaptonZap]

What is the mechanism on the cam sprocket?

CZ

[Stig / Major Tom]

What is the mechanism on the cam sprocket?

CZ

I'll ask the Vespa gang...
My guesses:
~~balancer to reduce engine vibrations

or, doing something with the valves:
~~mechanism to lower compression at start for lowly 6AH battery
~~pollution device for E-4 regs, lower emissions during deceleration (engine over-run)

I'll ask and report back.
Good question!
Stih

[Stig / Major Tom]

Yep, it IS a sprung weight to lower the compression by holding open the exhaust valve a bit longer while starting - which enables Piaggio to use a smaller starting motor (according to Robot, the Vespa guru mechanic out in SoCal.)
I really had my doubts about this guess - really, a 155cc needs to lower starting compression?!

Again, good question!

Stig