Bench starting Zundapp Bella engine

[Jonny The Goat]

Hello. Hopefully this is a easy question for people with electrical circuit ignition experience. I would like to start this engine without any of the bikes wiring in place. It looks and hopefully is simple. Really all connections are in generator case. First Bella's need a battery to start unlike most 2 stroke engines. There are only 3 connections in generator. As far as I can work out 1 is for lighting and battery charging and one or is it 2 for starting. The engine earths through frame of bike so as its 6v do I just need to connect live battery wire to the blue wire connection No 15 or Do I need to connect it to the red wire connection No 30/51 as well ? I would think it would then run battery neg connected on engine ? Though battery would run down after some time ? Can you also see from my drawings how battery charges, is it just through the green wire via the cut out reg that is fitted also in the generator ? It all seems really neat without having to have all sorts of electrical fittings all over the bike just the switch and lights. Hope someone can help so a I can run up the engine to see it runs before continuing with the restoration. Cheers, Jon.

[iansoady]

As far as I can see from the diagram, if you connect battery live to 15 and earth to the engine casing, you should have the basic ignition circuit. You can then at least get a spark. I'd disconnect everything else.

I wouldn't bother with anything else at this stage although the mere fact of the engine running will not tell you everything of course.

[Jonny The Goat]

Na, but would be good to know. bike was off road for years but engine looks like it was rebuilt and not run. Its still in frame but everything else is off so would like to see if it at least runs and go through gears before i pull it out and get frame powder coated. I must admit to me this generator looks very neat and unlike my other old 2 strokes do not have to contend with it demagnetizing
Would like to replace the condenser as the one on there has a dent in so may of been damaged, am I correct in that there is not any difference between a 6v an 12v one ? its a single wire condenser so if I get one of the same size so it fits in casing will this be OK ? Will try this one first but it looks to me to be the old 1955 one so may well be down by now.
 

[Jonny The Goat]

Just given it ago with live to the blue connection and neg to engine. Big spark breaking out at points but no spark at plug or even just end of lead. I am guessing this will be pointing to a faulty condenser as I think have had problem on something else like this before with very big spark at points and nothing showing at plug. Did put a meter on end of plug lead and do get a reading when kicking it over but not much and no spark so back to my other question can I use pretty much any condenser that will fit ?
 Cheers, Jon

[chaterlea25]

Hi Jon,
Yes pretty much any condenser will work
There may be a value stamped on the old Hella one? but + or - 0.2microfarad will be ok

John

[Jonny The Goat]

Hi John and others. Thanks for your advice. I have the condenser in my hand as am typing. Looks just like any other condenser at about 1.5" long though feels heaver than a small old one I found in my old parts from something or other, probably also faulty It has a number on it ZK034 / 46Z  2L would anything there point to how many microfarad it is or is that just a old part No ? We have a bike garage in town and will pop by tomorrow though will never find a exact match.
        Cheers, jon

[iansoady]

As said, any automotive condenser will do. It's pointless putting a meter on the plug lead while turning the engine over as this is likely only to fry the meter.