Sunday, July 7, 2013

Ben's 850 has a History

Ben Woolven dropped by to see us at the All British Rally this year with his very tidy and completely original Norton Commando Interstate 850. He's quick to point out that there's a story behind this bike which he imported from a collector in the UK.
It turns out that this is the actual bike that was displayed at the NVT stand at Earls Court London in 1975. Ben will not hesitate to compare serial numbers and show you the photo of a very pretty model sitting on the bike at Earls Court. Good on you Ben - thanks for a great story!

All British Rally 2013

In Newstead Victoria once again the riders were blessed with clear weather and a warm evening for camping out. This event keeps on getting better!

This is our opportunity to meet the riders and see their bikes and understand their chalenges.

It's a good thing I brought a few tools to assist with the installations and repairs going on around our site. We installed ignitions on a T150 Trident, Norton Commando and a Triumph Bonneville - all humming along nicely after the transplant!

The Trouble With Batteries....

Your electronic Ignition relies on power from the battery for its operation so it only makes sense to look at the battery when trouble arises with engine performance.

If batteries just lost a bit of capacity as they aged we would notice this and plan to get a new one in due course. Unfortunately they die in strange ways and sometimes suddenly, resulting in some of the most common troubles with our old bikes.

Here's what can happen. A battery with no load on it (everything turned off) may check out OK close to the nominal 12 volts but once the lights are switched on it may suddenly drop below 10 or even lower down to 8 or 5 volts. This is typical of an aged battery that's heavily sulphated but we can check for this by load testing the battery.

A bike shop can load test your battery or you can simply monitor the voltage with a meter for a few minutes with the headlight on (motor off). A good battery will power the lights for several minutes while maintaining above 12 volts.

Sometimes a battery can have one cell that dies resulting in really strange things happening.  The lights and horn may still work OK giving the impression that the battery is good when in fact it's struggling to function. The damaged battery can cause the ignition to misfire as the voltage fluctuates wildly under charge from the alternator.

In some cases we've even seen batteries that have short circuited to the frame or seat, burning out the wiring harness as a result. This can happen on some triumph twins if the battery posts are facing forward toward the fuel tank. Take care when buying a replacement battery that the terminals (positive and negative)  are the same way around as the original.

If your battery fails to maintain its charge it should be replaced without delay to avoid future headaches.

Technical - Idle stabilisation

" How does idle stabilisation work on the Tri-Spark Classic Twin Ignition?" a customer asked recently.

We know that it does work because we have a box of mail from customers including Michael from the USA stating that his 1972 Norton Combat went from being a little temperamental with the (other brand) of ignition to rock solid and a top performer with the Tri-Spark. He says:

"She started immediately and strobed one or two degrees off.The idle is a thing of beauty at this point.Confident is how I would describe the idle now.The progression through the rest of the rev. range is smooth, powerful and again, confident." - Mike Jetty

So how does it work? Without going into too much detail it works on the principle that the idle firms up with more advance and weakens with less. With digital control over the advance in the idle range from 500 to 1200 RPM we can get a result that continues to impress even the most discerning enthusiasts.