Wal Phillips injector
Reverse pull disc brake
Something for nothing - that's what everybody would like - a couple of magic words and suddely your bike develops another ten brake horpe power!
This never happens and so you have to look around and decide just where your money is best spent. The answer is to improve the engine, but this usually means buying very expensive parts and also spending long weekends in stripdowns and testing. But we have found an item that you can buy and bolt on which will give a reasonable increase in performance, and that is a Wal Phillips fuel injector. M M has tried these out in the past and found them to be just as clean running and realible as a carburettor but correctly unied, they will give a higher top speed, increase acceleration and sometimes both. We had a pair of Lambrettas on test this month and this was an opportunity to try out a new injector designed specially for scooters.
Made by the sane firm, this injector is similar to the existing types, but it is much shorter so that it can be fitted to a Lambretta or Vespa without having to cut a hole in the side panel.
Having a stub fitting, is fitted straght on to the SX200 that we were trying out. The tubing which normally servers as an overflow pipe to the Dell'Orto carb can be used as a petrol pipe from the tap to the injector. Wal altered the adjustment very slightly and then the bike was tried out. These are the times that were recorded:
0 - 30
0 - 50
We did not have chance to check the fuel consumption but it was not more than a couple of miles per gallon up on standard. This is a very small price to pay for a top speed increase of nearly 15 per cent. With the injector fitted, the SX200 gave a standing quarter mile time of 20.8 sec. and a terminal speed of 65 mph. This was only 1.6 sec. slower that the Royal Enfield GT, although the Enfield would continue accelerrating while the Lambretta run out of steam.
While the percentage increase may not always be so high on other makes of bikes there is bound to be an improvement of some form and this can be had at fairly low price. Not all bikes respond as well as the Lambretta but you can check up with Wal and get his advice first.
Tuning your fuel injector
da "Scooter World"
Having fitted a fuel injector you must remember that it involves different handling of the machine. This is not difficult, but it is essential to follow the instructions to get best results.
Starting the scooter
Flat spot. Delayed response to the throttle movemement or a flat spot signifies a weak mixture. This may be rectified by taking the connecting link down the threaded jet lever, having the lock nuts already finger tight only so that the adjustment may be made with the engine running.
Heavy smoke. Uneven running (eight-stroking) plus black or heavy blue smoke form the exhaust signifies an over rich mixture. This may be corrected by adjustment up the threaded lever. This allows the jet, which is in effect a jet-sized petrol tap, to shut off a little in relation to the butterfly, thus weakening the mixture.
Tuning the top half
Recommended Jet sizes
Fitting & Tuning instructions for the Wal Phillips fuel injector
Fitting notes: To allow clearance for JET LEVER it is sometimes necessary to file the RIGHT HAND (offside) nut, also with some machines the stud may have to be shortened. To avoid distortion of the flange ensure that both nuts are tightened equally. Couple up the original throttle cable, not forgetting to place the spring between the cable stop and lever, and then connect plastic petrol feed pipe. The injector is now ready for test.