Bosch ignition

I have a Sachs 505 1c and noticed the red wire for the pedal brake light is broke off ,the green wire is hooked up. Could this be the reason it will not run? Thanks

Re: Bosch ignition

I have a Sachs 505 and noticed the red wire that goes to the rear pedal brake is frayed and broken. Could this be why it will not run ?

Re: Bosch ignition

♣Slew Foot♣ /

Yes...

Rewire.

Re: Bosch ignition

I also have one of the wires at the handbrake broken off , just curious but why do I still get spark? Thank you maybe now I’ll have a running bike

Re: Bosch ignition

♣Slew Foot♣ /

Bosch ignitions the high-tension coil relies on the blue black wire being grounded to the tail the tale has a resistance factor of five to eight ohms and it requires that amount of resistance for it to start most people will bypassed the tail light safety feature by running the ground right to the frame on both sides tail and high tension coil basically you can put you are blue black wire on to the high tension coil mount as the ground return and you can also a fix an external condenser right at that mount.

The headlight horn running late tail light they all have to work they all have to be the right bulbs some of these has very low watt Magneto's they had a double tail light 2 bulbs one was a five when was the three what and the bulb for the headlight was 18 Watts so they're odd balls if you go to replace the tail light assembly or if you investigate the internals of the tail light housing there is ceramic resistor block sometimes it will get cracked the contacts on the tail light bulb itself bend them out make sure they're making good contact and don't have corrosion all over them most of it when you wire it is all ladder like the negative ground is the one side and the other side is the positive so basically you can run one wire directly to where it goes or you can wire them all up into a terminal block and then send them out where you need the juice making sure that there is a ground nearby that's good you also will have to make sure there's a ground strap on the engine block to the frame because sacks have rubber bushings on the mounts so it isolates the motor look into it let me know I was going to send it out Monday but I'll hold off to find out what you really need PM me

Re: Bosch ignition

Wow ,you know your stuff .Im sort of overwhelmed wit this electical jargon .Think I’ll try to hook it up by the book , not that I understand that either I’ll just try to follow every wire and bulb . The two broken wires are an easy fix However there’s a green wire that broke or cut off that’s zip tied to abunch of wires kind of neat and in der the bolt on plastic cover on the flywheel side of the bike not sure if it supposed to hook up anywhere Thanks again

Re: Bosch ignition

♣Slew Foot♣ /

Green is brake light related. They may have bypassed it already.

Re: Bosch ignition

Thanks again will check this out I checked the continuity on both brake switches and they were fine I located a rubber boot on line to cover the front brake wire connection.If they did bypass the rear brake light would the issues with the other wires still cause it not to run ?

Re: Bosch ignition

♣Slew Foot♣ /

Wiring should be clean no shorts or dead ends.

I have the spring and a few clutch disks. It will ship tomorrow...

Re: Bosch ignition

I’ll some free time tomorrow to work on the wiring . Should I take the clutch apart or wait to see how it works once we get it running? Thanks

Re: Bosch ignition

♣Slew Foot♣ /

If it compresses and moves leave it wait until you have the electricals under control

You know about the wiki?

https://www.mopedarmy.com/wiki/Category:Sachs

Re: Bosch ignition

Yes it’s really informative ,also watched the video a few times. I did the test they referred to ,it has some play but by myself couldn’t insert a feeler. Wouldn’t it been nearly impossible to run that bike without that torsion spring ? The previous owner that lost it probably couldn’t find a replacement, he had the bushing on the bottom

To try and keep it somewhat aligned, you had to pull the clutch lever out to release it and then it was hit or miss .Is there anyway to check the electrical system when we’re done going over it to positively make sure we got it right? I’m thinking there is but not sure I’ll understand it. Thanks

Re: Bosch ignition

♣Slew Foot♣ /

It will run just fine it's the starter all that spring does is it keeps that cup from contacting the clutch all the time you can run it but it might damage the point on the end of the arm or the clutch launch Bell

Re: Bosch ignition

That’s fine , I’m really in no big hurry. I also got a reply about the tension spring from another poster ,he must own a company called DOS. It’s to be delivered today along with a flywheel puller, that and the wiring will keep us busy Thanks

Re: Bosch ignition

♣Slew Foot♣ /

That's great I'm glad you found it so I'll put away the spring and I'll let you choose what you need just use the p.m. function

Re: Bosch ignition

I’m working on the wiring and have a question,hope it will not sound to hillbillyish.

The green wire coming out the magneto looks to be broken it’s not hooked up to anything but there is a green wire hooked up to that black terminal thingy with one wire going to the hand brake,the on the exact opposite there’s a green wire going to the foot brake. This wire must have been broken because it was spliced to the green wire that was going to the rear brake switch. Should that green wire coming from the magneto be spliced to those wires? If not where does it go and how is that wire attached to that black thingy? Hope this makes sense, Thanke

Re: Bosch ignition

♣Slew Foot♣ /

There might have been a resistor in the block to lower running light wattage.

Don't fret too much on the lone wire. If the blublk is grounded to the frame and engine.. The neg side is done. Rerun each brake and headlight positive. It should start. The decomp pin should be pulled up. Notoriously leak. Usually bypassed by short bolt.

Re: Bosch ignition

The black wire plunged into the coil is grounded to one of the bolts that holds the coil to the frame.there was another black wire in that mess of bundled up wires tha had a round connector on it that I grounded to the frame attaching it to the other screw holding the coil to the frame,is this correct? I took the headlight out to check the bulb which is good. There was a black wire with a round connector that wasn’t grounded.

So the loose /broken wire from the magneto is ok like that?Thanks again I feel like it’s getting closer to running

Re: Bosch ignition

Dirty30 Dillon /

> ♣Slew Foot♣ Wrote:

> -------------------------------------------------------

> There might have been a resistor in the block to lower running light

> wattage.

Resistors do not lower the wattage of a bulb. That is not their function, nor would it make sense.

Re: Bosch ignition

So basicly just leave it the way it was with the exception of repairing the breaks at both break switches ? Just leave the green wire from the magneto hanging ? Thanks again I got the spring and hoping to install and maybe get a compression check

Re: Bosch ignition

♣Slew Foot♣ /

if it's just the green wire out of out of the Magneto that is the brake light power the gray one is the running light power and the yellow is headlight / horn the blue with the black wire is the negative return it looks like a resistor when you open up a headlight bucket and you see that strip there they usually put it in plastic and it looks like a resistor but it could be a zener diode I don't know all I know is I seen enough of them in headlight buckets to know

Re: Bosch ignition

I got the spring installed ,it works but feels a little mushy when pulling the hand lever

I was finally able to test compression and it was only 25lbs, pulled the cylinder off and it looks like just a blown gasket. The nuts were almost finger tight and one was missing a lock washer The piston had very little carbon and the rings and cylinder looks to have no damage Gaskets ordered and soon on the way. Thanks again for the tips . I will get back to the wiring Thursday.

Re: Bosch ignition

That is LOW compression, I think you found your problem

Re: Bosch ignition

These bikes are fun to work on ,paid$300 and have had twice that much in fun,not to mention what my Grandsons are getting out of it

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