Back in the late 60's I bought a 1965 Lightning which was subjected to the usual fettling that teenagers inflict on their bikes. One of the improvements I made was to fit spacers between the carbs and the head. These allowed me to fit a balance pipe between the 2 inlet ports, which I convinced myself made the engine run better.
I have now bought myself another Lightning (trying to relive my youth?), which is also a 1965 model. This has a balance pipe as standard, with a spigot in each inlet port, which looks to be a production fit. And there was me thinking I had been very clever when I made my own! Does anyone know when this was introduced and why? Did it actually bring any benefits?
This bulletin will answer when.
Thanks for this Julian. My engine number pre-dates the change over number on the service sheet, so I assume the head is from a later engine.
Thanks again. It's very impressive knowing that there is so much knowledge so readily available. Would have made life so much easier when I had my first one.
Hi Martin,
Depending on how long they were, the spacers may have given an improvement as well as they would have lengthened the inlet which increases torque.
Dave.