YAMBRETTA 350 legend
If a 70mph Lambretta is too slow for you, take a look at Tony Holland’s YPVS 350 beast…
The Lambretta section of the build started life as a non-running GP150, which Tony bought for £450. “My inspiration for the project was a write-up of the Rossa 350 a long time ago. Then Lambretta legend Frank Sanderson built a 350 YPVS Lambretta and put all pictures at different stages on the internet. No dimensions, etcetera. But that was a big help.”
With the development of the project clear in his mind, Tony bought the swinging arm and both wheels from Frank, and then there was the critical issue of finding an engine, which Tony eventually purchased for £600 in 2010. Once the engine and frame had been purchased, it was a matter of adjusting the Lambretta frame to accommodate the original YPVS engine frame cradle, which would then be mated back into the Lambretta frame with minimal disruption. In order to complete this, Tony made his own jig to ensure that the re-attachments would be in 100% perfect alignment. In the meantime, Tony’s YPVS engine cradle was tack welded into position on the Lambretta frame, ready for the final welds to be completed.
Initially, Tony ran the scooter without a fuel pump. “There isn’t a fuel pump on the standard YPVS engine because the tank sits higher up and so gravity basically does the work. On the scooter set up the tank is a lot lower and so the flow of fuel doesn’t have the same momentum as on the bike. In the initial stages when I was getting the set up right the scooter was cutting out and I thought it was possibly the coil breaking down,” explained Tony. However, he discovered that the problem wasn’t with the coil, and with a bit more in-depth diagnostic thinking, a fuel supply issue was identified. As a result, Tony fitted a 2-6lb low-pressure fuel pump. “But then, when I got that fitted there were still problems! The fuel was now flowing into the carbs under too much pressure and was pushing past the float needle.” Tony focused in on the problem and it was then simply a case of reducing the fuel pressure to regulate the flow. Job done.
It’s no secret that cooling can be a problem with the Yambretta set up. As a result, the engine is cooled by the standard Yamaha radiator, which sits behind the inside of the leg shields, and air-flow is received through the cut-out areas of the leg shields. Also, if the temperature starts to rise, a thermostatic fan kicks in, which has an override button. Coolant is circulated by a standard Yamaha water pump, supported by a free-flow/high-flow item, which acts as a back-up/contingency. So far, however, it’s not been required. To support the lines and shape of the scooter, Tony designed an internal leg shield radiator cover out of one piece of sheet metal, and similarly the petrol and oil tanks are one-off items produced and developed by Tony. “I made cardboard templates of the items and got Martin over at MK to complete the alloy welding. The result is that the radiator cover hinges down to allow coolant to be topped up, and the tank holds around 11 litres of fuel, which is good for about 80 miles of range.” The paintwork has been completed in a TYCO-styled YPVS paint scheme; it looks fantastic and delivers the race styling perfectly.