Elektronik Sachse Ignition

[penman]

Has anyone else made the significant investment and fitted the Sachse ignition? I would be interested to compare notes!

Two years ago, I had a major electrical meltdown (literally!) and all the coils on the alternator stator were badly damaged. The ignition coil wasn't involved and did keep working, though it was somewhat overheated and I felt I could no longer trust it. The alternator re-wind was the subject of another thread on here and I paid the money and fitted the Sachse ignition.

Installing the Sachse box is straightforward, though it was a bit of a challenge to find somewhere to fit the new ignition coils. I eventually paid out more money and went for the "mini" coils from Dynatech. They are under the tank in more or less the same place as the original CDI boxes. Setting the timing statically is easy and will get the engine running, but it is then essential to check and re-set it with a timing light. This is a bit of a fiddle as a tiny movement of the rotor translates to several degrees at the crankshaft. It took several goes to get the advance to stop at the right point. The two plugs can be timed independently if necessary, but mine proved to be spot on.

The first thing I noticed is the starting. Hot or cold it is instant, I barely hear the starter, so that's the first advantage. The engine also seems smoother, especially under acceleration and I'm sure it has more power, particularly in the middle rev range. So I am generally happy with it. There is a downside though in that I have found it more difficult than previously to set good idling. Hot or cold, it will idle well, but if I set the carbs up for good hot idling, it tends to die at idle when cold. On the other hand, I can set it for good cold idling and then it tends to race when hot. I don't really remember having this issue before. The answer is to start the engine, ride away on choke, close the choke asap and hope it'll have warmed up enough by the time you have to make your first stop.

So my thoughts are that this is by no means an "essential" upgrade and the original system does have the advantage that the ignition is independent of the 12v supply. However if you are having any problems with the 40+ years old ignition components, this is well worth considering and will probably give you a better running bike.

Any other thoughts on this?

Regards,

Joe.

[72degrees]

This report may convince me to make the investment. The 2c/375 has been a good starter since I went with the NLM modules, conventional coils and OEM red type II pickup, but has been slightly sulky lately - not good for a bad hip.

This may be carburation though as I had the same not wanting to idle, or indeed run properly, without 'choke' until well warmed up issue. So as an experiment I upped the idle jet size. Bear in mind this is on a tuned engine with L5 cam and PHBH 28mm carbs. I thought that had done the trick, but fear I may have gone a little too rich. It was uncharacteristically hard to start after sitting in the sun all day at Shelsley Walsh last month. Thought I might have to get at least the front plug out to air the cylinder, but at the 10th attempt I managed to catch it on the throttle with both chokes off.

It might be the spark not up to snuff though as the module has been fitted for quite a while and the ignition winding was last rewound some years ago, so more investigation required.