Vespa VBB clutch side seal replacement

Vespa Engine Tuning

Vespas have two stroke engines and are performance tuner’s dreams. They are not quite as tunable as a Lambretta (but they are also more reliable!) but you can go pretty far down a rabbit hole making improvements. As a general rule of thumb, the more you tune the less reliable you make your bike, the more fuel it will consume, and the greater the chance you will size the engine riding at some exhilaratingly fast speed your scooter was never meant for. But that is part of the joy of scootering!

I decided to do a straightforward road tune using a Pinasco 177 2 port kit. This is a bolt on option with no engine case modification required. It should allow me to cruise at 45mph and hit 55 for brief periods of time. I hardly ever drive at those speeds! The kit was also a good option because my existing setup had about 11,000 miles and it was probably time for an oversized piston and cylinder hone. So for the same price I’m getting a performance boost.

Here’s a picture of the kit. It seems well thought out and has been installed on a lot of bikes.

VBB Restore Tech Design Works
Pinasco 177 Kit for Vespa VBB 150

The instructions aren’t very good though so you will have to look for better info on the internet. I recommend the Vintage Scooter Builders Showcase on Facebook.

To get full advantage of the kit you will need to upgrade the carburetor and the exhaust. The 24/24 carb lets more gas into the engine, and the shape of the performance exhaust acts like a valve to improve performance.

The engine hadn’t been apart in 24 years and sat unused much of the time, so based on expert opinions I split the cases and replaced the seals. Since the engine was already out of the bike this was the best time to do the work.

I built my own engine stand and went at it.

Now that the engine is done, it’s time to work on the brakes.