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Request for assistance - 750S with electronic ignition

Posted: Mon Apr 10, 2017 12:13 pm
by Blacklightning
Evening All,

So looking for some help with a 750 Sport fitted with electronic ignition.

Bike is a recent full restoration from a well known restoration shop, all new and shiny and less than 1500 km on the clock.

Electronic ignition is BC0500006 ELECTRONIC IGNITION 750 R/C Sachse Electronik, Germany.

No ignition problems so far.

I took the bike out on Sunday (well I tried).

About 1 mile to Petrol Station - engine dies as I pulled in - fuelled but could not restart.

Got bike home, no spark on either cylinder.

Looked at battery which had been on a trickle charger, low electrolyte.

Swapped for battery off another bike - healthy spark - bike fired and ran.

Went out, half a mile - bike stopped and refused to restart.

No spark on either cylinder.

Let bike go cold, first kick and it fired and ran. 3 or 4 minutes stationery then stopped.

No spark on either cylinder, would not restart.

So:

Battery now topped up and fully charged (and I had used a battery off another bike too - so battery OK methinks).
I know that electronics can be very sensitive to iffy batteries but whilst I know the battery I first went out with had low electrolyte levels, the battery I swapped it over to was fully topped up, healthy and had taken me out for a run the day before on a 900ss.
Connections to key switch look sound.
Earths sound.
Fuse box clean and polished, took fuses out and cleaned and replaced.
Changed plugs for new ones - no difference.

I think it is therefore something heat related in the electronic ignition but I am not familiar with what tests to do.

Any suggestions?

(I mean to get it fixed, not stuff like put the points back on etc thanks lol %^) ).

Regards

Stuart

Re: Request for assistance - 750S with electronic ignition

Posted: Mon Apr 10, 2017 3:00 pm
by BevHevSteve
does the battery drain from a full charge to low or dead sitting for a few/several days or does the thing stay fully charged when sitting? (this checks for a drain somewhere).

Re: Request for assistance - 750S with electronic ignition

Posted: Mon Apr 10, 2017 3:25 pm
by Blacklightning
Hi Steve,

Not sure as I keep it plugged in to a Optimate trickle charger pretty much all the time.

Do you think there is a possibility of an open circuit somewhere leaking to earth?

Regards

Stuart

Re: Request for assistance - 750S with electronic ignition

Posted: Mon Apr 10, 2017 3:30 pm
by BevHevSteve
unplug the optimate and check if there is `-*

Re: Request for assistance - 750S with electronic ignition

Posted: Sat Apr 15, 2017 11:53 pm
by Peter Mille

Re: Request for assistance - 750S with electronic ignition

Posted: Wed Jun 07, 2017 5:17 am
by skidstar
Check your plug caps,they MUST be 5k ohm resistor caps or you can get oscillation in the ignition system.
I had the same problem.,very simple mistake to make.
Ran my bike up on dyno and 4 (on my bike) was best curve,it ran well on 5 but 4 gave another 3hp in mid range and 5hp up top,all other curves were useless.

Re: Request for assistance - 750S with electronic ignition

Posted: Tue Nov 27, 2018 8:20 pm
by 1funduc
The Sachse ignition is sensitive to the quality of the electricity given to it. I had spoke with Volker before he died because I had fried the new ignition on my 750. He stated that the old voltage regulators allow voltage spikes and highly recommended installing a modern voltage regulator. He said he would redesign the curcuits to prevent it happening on the new products but I don't know if he ever got that done before being killed. Great ignition. I've installed them on a number of bevels.

Re: Request for assistance - 750S with electronic ignition

Posted: Tue Nov 27, 2018 9:23 pm
by Peter Mille
Can you recommend a brand regulator?
I'm still running the original Ducati Elletronica one, together with a new Sachse ignition on my Mille....

Re: Request for assistance - 750S with electronic ignition

Posted: Wed Nov 28, 2018 10:42 am
by BevHevSteve
I keep a couple on the shelf, either will work.

https://store.bevelheaven.com/index.php ... =regulator

Re: Request for assistance - 750S with electronic ignition

Posted: Wed Nov 28, 2018 11:30 am
by Peter Mille
Image

This is on my Mille, so I guess that's allright with the new Sachse ignition...