Modern Vespa

I understand the pros and cons of running a lighter flywheel on a revvy street racer type of setup, but what about going heavier than stock on a long legged, mile munching thumper? I have a 1987 PX200E engine with a problematic flywheel (part of a magnet is missing), and I have a perfect Ducati flywheel weighing in at ~3KG which must have originated on an early P200E or a later Rally 200. Any benefit or negatives in using it on a Pinasco 225 kitted motor with an upgear, or should I look for a late PX200 flywheel at ~2.1KG?

No reason not to run that heavy flywheel since you're not looking for quick revs.

Jack has that same flywheel on a P200, I believe, and it idles at 800 RPM's and will probably blow the cowls off a lot of lightened flywheel bikes.

I am a fan of the heavy fan wheel

Looks like Jack's touring P2 has a 2.3kg flywheel, which is the later elestart type. Without the starter ring, it's 2.1kg by all accounts, and these are still available but pretty expensive.

I'll give the 3kg flywheel a run and see what I get

I have copied this image from one of sime66's threads and have magnified the area in question. Sime has this flywheel with what looks like a chunk missing from one of the magnets. Mine has exactly the same bit 'missing', and I thought that it was defective. Maybe it's how this type of flywheel should look? I must admit it does seem very clean and regular, as if it is part of the factory design.

The flywheel makes a kind of ticking noise, and I've tried three different stators. I'm trying to figure out if the flywheel is toast or if I can save it. Any ideas?

[edit] mine is a 1987 PX200E flywheel by the way

A friend who races vintage sports cars wrote this :
" A lightened flywheel does very little to contribute to on-throttle speed changes (in-gear acceleration). That's such a relatively slow event, that the difference will be impossible to feel and difficult to measure. It's fractional at best.

The real purpose (and this is why it is a race-only tool) is to allow the engine to spin DOWN faster. That allows the driver to shift up quicker, as the time they have to wait for the engine to slow enough to match the next (faster) ratio is reduced. Thus, acceleration is improved, but PRIMARILY through shifting technique."

if we talk small frames, the lightened flywheel is usually the difference on whether your crank taper snaps off or not, at least on the small cone crank....

anecdotally, I notice the difference in willingness to rev when you go down on flywheel weight. it's not huge but it is perceptible. that's why I used to send all my flywheels to hot rod al for lightening. ah, I miss that guy.

Regardless of what we do as part of our go faster exploits, does anyone know why Piaggio lightened the P200 flywheel from ~3kg (early P200E) to ~2.3kg (late PX200 with elestart ring)? Changes like this tend to be about improving the product, but what deficiency did this change address?

No doubt it was something to do with the fly side bearing and cruciform wear.

Not snapping the taper off is definitely the goal when tuning. My 20bhp 200 has been running the 2.3kg for many years and seems fine. Will do a winter engine split this year and see if anything needs changing.

Speedy has small taper VBC150 , with plastic flywheel.... and clutch-side of crank snapped off!

I read many moons ago that the flywheel & clutch assy (& most likely, weight of crank from bearing outwards) need to weigh the same each side to keep things in balance