79 GS750 wiring no battery

what rpm do guys usually try to set the idle at?

Yes, that is it, and is a genuine Bosch relay. Now go to an auto parts store and get the wiring pigtail harness that comes with a nice 4 pin molded plastic plug that fits perfectly on that. You could also get a generic relay from the auto parts store, but that Bosch one is probably better Chinese quality! They're probably all made in China now. Slight chance the real Bosch is made in Germany.

got the relay today, made in germany! who would've thought

[posplayr]

The schematic has a few problems related to short cuts.

It is drawn like a block diagram with signals between it so it doesn't look alike an electrical diagram. For example, the Dyna-S does not show the chassis ground which it requires. Basically, it means that we have to take at faith you have identified all inputs and outputs to each device with your representation. Since I would have to guess and fill in what is in each block, the schematic is not meaningless but so subject to interp[retation to be worthless to anybody else but you who knows what you meant. Basically, this schematic is missing many details which means it is for "your eyes only".

You have only three color codes to indicate ground, plus and signal. This such a dramatic reduction from normal GS schematic that it is hard to tell without redrawing. Not aking a distinction between always on HOT (RED)and switched HOT(ORANGE) is a serious transgression. Another is not distinguishing between chassis ground, frame grounds, harness grounds, and charging grounds. If the only thing that mattered was voltage, then that would be OK. But what is most important is to understand how all currents return to their source. Your representation obscures that. Which makes the schematic severely inadequate.

Other than that, I would say you have captured many things and I can see many connections. So in retrospect, I can't call this a schematic for the reasons mentioned which means nobody can do an evaluation of it except for you(because it is only you that carries the missing information in your head).

hoping someone can look at my schematic, thanks

sorry for the late reply again, and thanks for taking a look. The battery is the antigravity xps, it's just a brand and smaller than your average, the thread title is misleading since I give up on the no battery thing shortly after making it, but I'm still trying to figure out the wiring going this route.

With the exception of the battery dilemma, what are your thoughts on the latest diagram?

[posplayr]

You will either a battery or s super capacitor to dampen out the high frequency chopping coming out of the R/r . The R/r is not a power supply with smooth out put. It is only smooth with the capacity of the battery

okay, that one hit the light bulb for me (took me long enough). I got the most recent update attached.

I would have added another relay for the lighting but I'm using all LED lights so I imagine that wouldn't be necessary with the amount of power they will be drawing, what do you think?

On top of the turn signals and horn not being necessary on bikes in colorado, and this may come as a complete shock (sarcasm), but one of the last 4 owners pitched the turn signal, horn, headlight, kill switch assembly. I guess I'm just going to cave into getting a new assembly, what do you think of this one? https://www.ebay.com/itm/Motorbike-L...sid=m570.l1313
Do you have any recommendations since I need to buy a new one?

[Chuck78]

Incorrect.
30>87 should not be fed off of the same switched ignition source, that defeats the purpose of the relay & just adds pointless excess.

The 10a fuse giving power to 30>87 should be fed direct off of the battery/regulator-rectifier connection. The whole point is to take the load off of the ignition switch to improve reliability and available current flow through the switch contacts. The 85 or 86 relay 12v+ trigger wire doesnt need any additional fusing, but it is supposed to activate the relay when the ignition key switch AND RUN/START "KILL SWITCH" are both on.

The same thing is commonly done for the headlight power feed. This takes the biggest electrical load on the entire bike off of the keyed ignition switch & gives it a dedicated set of relay contacts (headlight relay trigger wire would come straight from the ignition switch, and not feed through the run/stop kill switch).

These relay feeds give you both a better spark / brighter headlight, AND less of a strain on the keyed ignition switch AND RUN/STOP "KILL SWITCH." In other words, a more reliable electrical system.

Where is your handlebar controls integrated run/stop kill switch, by the way???????? This is essential for safety, and is a "hipster art project bike" mistake not to have one. It will also make carb tuning very hit or miss, as you cannot do proper plug chops without instant access to the kill switch while operating throttle/clutch/brakes simultaneously.


The point of the relays is to make the bike more reliable AND deliver more power to the critical components by taking the strain off of the ignition switch/kill switch, and giving a more direct power source feed to the critical components (ignition & headlight). Ignition switches can only flow so much through them reliably, & you are placing the entire bike's electrical system on just 1 wire & 1 set of electrical contacts. Simple wiring, yes. Reliable/good idea? No.

Is there a horn on your diagram? If not, thats both a safety & legality issue.

Correct your diagram and re-post.

Alright I labeled the relay hookups in my diagram attached below, let me know what you think of the newest diagram version, I really can't thank you enough for all your help Chuck. I tried to find a little bit more about how to wire in the relay, and I get the basic concept, but I'm still a little lost on it. I think a couple votes of confidence would take a huge load off my back.

[Chuck78]

30 & 87 will be the fused "line" wire from your battery, and the "load" wire to the Dyna and coils.
85 & 86 will be the electromagnetic coil that switches the relay on, one will be a brand new ground wire you will add, the other will be the cut and extended orange wire that powers the ignition coils. Or in your case I guess, since you are making your own wiring harness from scratch, the power feed wire from the ignition switch and kill switch.

[Chuck78]

Yes, that is it, and is a genuine Bosch relay. Now go to an auto parts store and get the wiring pigtail harness that comes with a nice 4 pin molded plastic plug that fits perfectly on that. You could also get a generic relay from the auto parts store, but that Bosch one is probably better Chinese quality! They're probably all made in China now. Slight chance the real Bosch is made in Germany.

Is this the right relay to use? https://www.ebay.com/itm/GENUINE-BOS...itleDesc=0%7C0

I attached a new diagram below, Lmk if this is looking like an A+

you're the man chuck! I spent about an hour on the phone with a guy from dyna yesterday, I mentioned to him that I was wiring the thing from scratch, but I don't think he quite got it. I got the wiring and the rotor position figured out, and I got spark yesterday when it was supposed to spark, but not long enough to get it timed. I'm still not sure exactly what the problem was/is since I left out a couple things, but I'm almost certain the thing is fried.

The bike wasn't running when I got it, the carbs were off and mostly disassembled, the wiring harness was off and demo'd, no battery, and no lighting.

I got the carbs cleaned, rebuilt, and on for the first time in god knows how many years, but I was working on the timing before I was going to fire the thing up (although it sounds like timing it while the bike is actually running is the better way to do). Also noticed the carbs were hard to fit onto the boot, so I think since the carbs were left off, the boots have shrunk and no longer fit very well.

[Chuck78]

The 30 amp fuse should be a 20 amp fuse, and it should be before the ignition switch, possibly in between the regulator rectifier and the battery I believe is where it should be. Refer to Jim AKA posplayr's posts in his signature file. Find any post by him, and look at his signature file, you will find many very helpful electrical links.

You also may want to take the air cleaners off and spray a little starting fluid in each of the carbs and then try and fire it. Even if it just backfires, you know you have spark somewhere then. That may definitely indicate that you are 180 degrees out approximately if that happened

[Chuck78]

Also, make sure you have a darn good engine ground strap, heavy gauge wire, from the engine case bolts up to the single point ground. Test and make sure you have a good 12.7 volts or whatever at your ignition coils.

DID YOU ADD A RELAY TO POWER THE COILS AND DYNA-S????? This is CRITICAL, I have literally a pile of bad Dyna S ignitions that got fried from not having enough voltage (11.7v MINIMUM, measured AT Dyna red wire & coils power wires) due tp 12 feet of old wire, a dozen dirty loose old wire connectors, and dirty/loose/worn out ignition and kill switches. I clean all of those very well and check the riveted terminal connections on the ign/kill switches, but I STILL add a direct relay powered feed straiggt from a 10a fuse and battery. Use old Orange ignition coil wire to trigger the relay, add a new ground on the other side of tge relay switching coil.
You can even buy a plastic harness pigtail plug at the auto parts stores that plugs straight into the standard automotive 12v relays. You only need a normally open single pole Bosch style relay. 4 terminals. Common= Line power in, NO = load power out, other 2 are ground and switching trigger power in, & are not polarity sensitive.

Once you make sure you have the wires phased correctly and the rotor positioned correctly and not 180 out, try to start it with the Dyna aluminum backing plate rotated almost all the way clockwise, with just maybe 2mm of gap showing to the left of the screws that hold the Dyna to the engine case. That is generally about where they all end up at. But you definitely need to time it, and you should try and at least find a used inductive pickup timing gun on Craigslist or something.