Back again...79 750F Starting issues

[iddqd]

So the bike is coming along nicely, I'm confident I'll get it up and running soon, but I'm having a particularly difficult issue.

The battery will be charged to spec, the bike will start, run and idle like poo, I can hear knocking coming at low RPMs, I think the knocking might be isolated to the spark advancer/pulse generator unit on the left side, regardless, once I stop the bike OR the bike just idles so poorly it dies, I can't get it started again, it acts as if the battery is did. If the bike does die on it's own the pulse genny will be knocking around inside the assembly.

The bike also idles pretty erratically, but that could be carb syncing issues, or maybe a gasket leak that hasn'tbeen isolated yet? don't worry I'll save that for another post, I'm sure.  

I did all my necessary checks of the alternator and the stator, all the wires associated with the alternator and stator, those checked out OK.

The wires for the spark adv/pulse gen also checked out OK, the screw driver test to check the spark also proved successful, so I'm really not sure what is going on.

I should mention the bike came from a PDO (previous dreaded owner) and he actually replaced the starter solenoid with one from a car and rigged up some ridiculous wiring system that involves hot glue, yes hot glue stuffed into the plastic connector and wires jammed in. I know I should probably replace that before asking why the bikes electrics aren't working properly, and yet here we are.

[Re-run]

Yeah, you should probably replace those parts. Good thing is that once started, they don't really play a roll in the bikes operation. How well does the bike rev up? What rpm is it idling at?
Idle rpm should be around 1000 rpm or so. When you start getting lower, the engine chugs and it will make more noise. maybe not the noise you describe but hard to say without hearing it.

Also, a bench sync is usually adequate to get things going without too much issue. if the carbs were not bench synced, that could be part of the issue. poor sync will cause more noise as well.

I would also rev the bike to 2000+ rpm and check the battery voltage. Make sure it is above 13 volts. I had a battery that, at rest, would show correct voltage. Put a load to it and it flat lined instantly.

[iddqd]

Re-Run thanks for the reply, and that's what I'm thinking about those parts too, I know they don't play any role in the running of the bike, but god damn does it piss me off on how it looks and I'm not one for shoddy halfassed repairs, or else I would've been riding this bike back in May.

The bike itself revs fine with the throttle, there is a bit of reactionary delay with the choke knob tho, it takes a second to react to being pulled out or pushed back in.

When I adjust the idle to around 1000 is when it starts to behave a little erratically, I did clean and bench sync (to the best of my ability) the carbs, that was actually my first real big project, but I didn't break the bank so to speak and submerge them in a can of carb cleaner, I just did everything by hand, so maybe I didn't do such a hot job?

Around the 1000 RPM mark it is doing a chugging and klunking noise, pretty rhythmically, I haven't figured much about it yet because I'm just trying to sync the carbs but if I stall the bike when it's running I have maybe one more shot to get it started and then the battery is back on the charger.

I will check out the voltage when it's reving up today.

[iddqd]

Update, found out the voltage regulator was bad, and that I completely forgot to test it earilier.

[Re-run]

Did you find that while checking voltage? I remember having a bad regulator in a car, faster I went, the brighter lights got and the faster the tape deck went. Blew headlights like crazy too.

Also another reason why I won't put a new lithium based battery in these old bikes. I would rather have a battery leak from overcharging as opposed to bursting into flame.

[shinyribs]

Re-run wrote

 I remember having a bad regulator in a car, faster I went, the brighter lights got and the faster the tape deck went. Blew headlights like crazy too.

Haaaahahahahaha!!!