DMC Ignition

[dave48]

I just installed a new DMC ignition. I did the set-up on curve 1 per the instructions and everything works fine. Any suggestions on the best curve setting for a 78 Jarama with low miles.

 

[Laverdalothar]

you can try any curve with 32?max. However, some use the 28? curves and give a bit more pre-ignition at idle (static timing), so that the max is 32?, too. shall give a better idle and avoid the bike to stall in idle I heard, never tried it though.

 

[Dellortoman]

The mileage is not relevant when working out the optimum ignition timing. The main variable is compression ratio. Higer compression engines use less advance than low compression. If you have high compression pistons, then aim for around 28? to 30? max advance. If you have flat top pistons, then 32? to 34? might be better. If you have the opportunity to put the bike on a dyno, adjust the advance for maximum power.

 

[laverlesmains]

slight hijack..

my 3C is running curve 10, and seems to be fine but in checking today it seems that it's idling at about 12-15* BTDC.    I double checked TDC, measured 42 mm per the green book, and it does seem to go to full 32* at 4000rpm ish.

I've checked through a lot of threads on the forum and haven't seen anyone who idles at 12-15* BTDC..

Oh, and my stator plate is fully anti clockwise so I can't rotate it further anti clockwise to advance the timing.

 

[dave48]

Laverlesmains
Thanks. Curve 10 was the one I was looking at but was concerned because it didn?t reach max advance until 6000 rpm?s per chart supplied with ignition. If it hits max advance of 32? at 4-5k rpm like yours that would be great.
I can?t comment on the idle, haven?t got mine to idle yet.  Running very rich and backfiring in the exhaust.
My stator plate adjustment is right in the middle of slot.
Dave

 

[Xav]

I try curve 10, 11 and 7

Curve 10 is my favorite. It is on this position that the motor behavior is the best, most enjoyable, and aggressive past 5000 rmp/min

Xavier