Bmw r45 starting problem with motogadget

[Davidj4310]

Hi
This bike is my 1st build & a custom bike. As I changed the handlebar switches etc I thought I'd go with the motogadget v3 to make the wiring simpler which with the light,switches etc were great!!! Problem is with running the bike!!
I've got spark, fuel to the carbs (they've been rebuilt) but the problem the point heel MELTS & if I do get it running backfire from 1 side at a time is this a problem because of the motogadget or something else?
Thinking of getting a Boyer electrical ignition system & new regulator/rectifier to do away with the old?

[Barry]

but the problem the point heel MELTS & if I do get it running backfire from 1 side at a time is this a problem because of the motogadget or something else?  

You have points in a can ignition, one feature of which is a need to lubricate the points cam at every service with grease, there being no other means of lubrication.  That said I wouldn't expect the points heel to melt unless the engine was run at high revs with the cam bone dry, rather it would normally wear quickly from lack of lubrication and probably make a noise about it as well.

The backfiring may be an ignition timing error. If you do a static timing check, the points should just open when the S mark is aligned with the chisel mark on the side of the timing window.

[Davidj4310]

I'll try with lubricanting the camshaft but thought it could possibly be too much current running to the points because of the motogadget? The coils seem to get very warm,quickly possibly faulty?
What is the spark pattern do they run with a wasted spark or 1 at a time? thought this could be the reason for the backfire from 1 side at a time because there's a spark when inlets open?  
Ive got no real mechanical knowledge so sorry if I'm talking rubbish.

[Barry]

I have no experience of a motogadget  but if it has a tacho function it will pick up an impulse signal from terminal 1 on the front coil. The only way that could cause the coil to overheat is if it is permanently shorted to ground - but then the ignition system wouldn't work. if you want to check if the motogadget is causing the problem just disconnect the impulse wire.

Leaving the ignition on with the points closed will cause the coils to get hot but it won't usually damage the coils. That's assuming you have standard coils or if a replacement has been used then it is of the correct total primary resistance i.e. in the region of 3 ohms. If you have used  a coil of lower resistance then that will also cause the overheating problem.  If you have a meter you could try measuring the current that the coils are drawing.  With the ignition on and points closed expect approx. 4 amps. With the engine running it should fall to 2.5 amps at idle and below 2 amps as you rev the engine. Taking those measurements with the tacho impulse wire connected and disconnected would confirm if the motogadget is drawing any additional current.

It is a wasted spark system with both coils firing at the same time. Wasted spark ignitions can cause problems on V twins where the cylinder timing gets close to an inlet being open but not on a flat twin.