A question that's been asked and searched for a fair bit recently, so I thought I'd post the answer The pistons in all cylinder kits, not just Malossi 70cc big bore kits, have a little arrow on the top of the piston. This arrow faces the exhaust port, so it is generally facing down on horiztonal engines and towards the front of the bike on vertical engines. Fitting the piston the right way round on big bore cylinder kits is extremely important, since the big bore piston rings arn't complete (they need to split to squeeze over the piston), they have a point in the piston there the two ends meet. These two ends generally line up between the middle and outer transfer (intake) ports on the rear of the cylinder providing you have fitted the piston in the right way round.  Fitting the piston backwards on a big bore cylinder kit will result in these two ends opening up slightly in the exhaust port and possibly catching.  As well as this a lot of pistons have a cut away piece for helping intake induction on a certain side, and sometimes are cast / machined to take more pressue on the exhaust / thrust ...

So you want to make your scooter faster?  Malossi manufacture the fastest, best performing, best quality tuning parts available for mopeds and scooters, and work closely with the major scooter manufacturers to build the best tuning parts and accessories available. Every national and world class championship winning scooter has been tuned with Malossi parts, simply as they're the best tuning company in the business!  If you're ever unsure on what to go with, 99% of the time Malossi are the best to go for, although they're not always the cheapest. Does that mean there are better value for money alternatives?  Yes, but they're not always the best performing, so it's usually a careful balancing act when tuning scooters with a budget, as a lot of cheap tuning alternatives to Malossi are of poor quality, however there are some other manufacturers out there that are 99% as good for road tuning compared to Malossi, and half the price. Generally there are 3 main things when tuning the modern automatic scooter we carry out: performance exhaust replacement (fitting a race pipe), 70cc performance big bore kit, and an aftermarket performance variator.  After this tuning gets very expensive and isn't cost effective, nor suitable for road ...

Piaggio Performance Tuning Guide To compliment to the Moped & Scooter Tuning: The Facts article, here is my personal reccomendation on how to tune Piaggio scooters, at my old work we have used this setup literally on every 50cc scooter we tune and have never had a kid come back from his test ride without a smile on their face. This article covers any Piaggio engine based scooter, so will apply to all Gilera, Vespa and come Aprilia scooters, but beware that exhausts may be specific for certain Vespa & Aprilia models due to bodywork differences. Although a little different in order from the previous article, these are the three main things we to do Piaggio scooters, and most people do not require anymore! 1. Fit a performance Race Pipe / Sports Exhaust We reccommend the Giannelli Reverse (or the Giannelli Extra if your budget can't quite stretch that far) for Piaggio motors (Remember all Gilera, Vespa and later post 2004 Aprilia's use the same motors). Firstly, this exhaust is sold as a legal aftermarket exhaust, not technically a race pipe by law, so it's got a nice little stamp on it which means it'll pass an MOT, as well as coming with a warrenty, so ...