Modern Vespa

How are you liking the 60mm Mazzy bell crank so far? I'm interested in hearing about the long term durability of it. I'd like to go that route in my obnoxiously red PX210, but i keep hoping that Uncle Tom will make their own version. My only hesitation is that the Mazzy crank don't have any oil slots cuts into small or large con rod. And do you think the pin will require any welding to keep the webs from twisting?

I'm now on my second Mazzy bell in my GL's (Stella reeded case) motor. It's a pretty solid piece of kit, but...I'm on my second one. The first one lasted over five years, I think. I'd have to dig through old posts here to figure out exactly how long, but it was a long time under hard use, for sure.

The big end pin on the first one worked its way loose and slid in a couple millimeters at one point, demolishing the big end bearing along the way. It's on the shelf, but if I ever get a hydraulic press, I may have a go at repairing it just for the experience. I'll weld the pin if that happens, though.

It made a definite difference in terms of waking the motor up. It was part of a larger new build, so I can't say exactly how much of the difference was the crank vs the any other change, but the GL will happily run at 75 MPH for longer than I'm comfortable sitting at those speeds and will pull over 70 uphill. That's on 22/65 and PX gearing.

Rob Hodge gave me the idea back when he was still active around here and I went for it. Good call on his part.

Similar story to CM, Since the Mercur thing Mazz cranks are better. Used them very hard in high hp engines and no issues worse than many other cranks. Biggest disappointment I've had are with the cool looking, expensive Pinasco cranks. Oil slots let as much oil out as in. Not critical imho.
One thing I forgot to mention, this bell crank needed a conversion small end bearing. They were out of stock at the time. I found out an early Yamaha YZ125 small end is the same size, delivered locally and inexpensive. Been running fine.

It was raining most of today. Been planning to have a look in the 181 cylinder. And while there adjust the port timing, as per the mentioned plan, or there abouts.
Once the cylinder was finally off (These 125 blocks are so much harder to swing the engine). All looked really good, bore smooth, piston black, just fine wear marks. Much to my relief. Been running it quite hard and ridden about 1000 miles now.
Was feeling the power tail off too early and that always means lack of blowdown or low transfers or both.

So, raised the cylinder a little with another base gasket and ground 0.55mm out of the exhaust port to raise it slightly. This is still well under the maximum for this pipe but I only want this to be quick like a touring set up.
I did, find some sloppy work in the exhaust port. As I've now raised approx 2.5mm from original, the port roof was looking like a wizards sleeve. Out with the big burrs and flattened the roof out. Lots of swarf. Polished it after. Much happier now. Could hear the extra port timing on start up. Has even more of a cracking sound when revved. like it.

Timing now at 130/185/27. Not going to be raining tomorrow. Will see what happens out on the road.


Just one careful owner. Poilished and chamfered. Quick wash then ready to get oily again.

That Port looks fantastic, all polished up. I'm going to do the same next time...

EDIT: I appreciate you explaining what you're doing and why. I'm taking notes!

You sure the cracking sound isn't piston rings hitting the roof of the port?

Sounds like it's gonna be good to ride

If I've made the port too wide it's me that will hit the roof.
So far It's that cakaling, rattling sound a 2 stroke expansion makes when the jetting is ok. It got sharper. Might need to raise the needle and up the main now or just change atomiser. Will be fun testing.

Polished does look nice but next time I see it it will be black as usual but will wipe off easier!
Another point I didn't mention. This scooter has a full P200 EFL gearbox and it was pulling really well in 4th from low rpm, too well. This is a sign the port timing is lower than needed for what I want it to go like. I could have upped the gearing but chose to up the powerband. Will have some idea after today's ride. Bright sun and chilly.

Definitely better. Still pulls 4th too. Did a 45mph to 70mph 4th gear roll on, directly into heavy wind at one point. This kit on a 3 speed 2 port would be perfect.
Didn't get the jetting completely finished but will do tomorrow. Tried a bigger atomiser but was too rich.