1977 CB750 Deviant Hell Ride

deviant said:
I went with this reg/rec: http://www.ebay.com/itm/331288984721?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

Notice no white wire on the reg/rec. White from the stator goes straight to the power buss. Yellows from the stator go to yellows on the reg/rec. Red to hot side of the battery and the kill switch. Green to ground.

How does that work? Wouldn't the field coil be getting 12V all the time and cause an over voltage situation at high RPM?
 
john83 said:
How does that work? Wouldn't the field coil be getting 12V all the time and cause an over voltage situation at high RPM?
Excess voltage goes to ground. I max out right around 13.6v, iirc.
 
After chasing gremlins in the charging system on this bike for months, I've finally gotten it all sorted out. First issue was the stator, which got replaced and seemed to get it running for a bit. Second issue was a bad reg/rec that apparently was wired for a DOHC yet marketed for an SOHC, or something like that. Bought the cheap reg/rec off eBay like we talked about up there ^^^ and it ran well for a bit. Third issue was the field coil. At the beginning of the summer, the ignition seemed to start dropping out and fouling plugs. The charging system could hold a charge sitting in the garage at idle, but as soon as you take it on the road voltage would drop below 12v. You could rev it up to 12v+, but it got to where it was worse and worse. I tested field coil at 7.8 ohms resistance, so bought a unit off of eBay. On a hunch, I replaced all of the wire to the field coil and instead of bullet connectors I soldered the wire under the shifter cover. A layer of glass tape, individual shrink wrap, bundle shrink wrap and an abrasive resistant sheath later and I hooked it up. Finally, after all this time the bike might actually charge like it's supposed to...

Lesson: Replace every fucking millimeter of electrical wire on a bike made before 1999.
 

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You bringing this to the Cape Fear Kickdown? Or is the Beemer making an appearance? Glad to see this running right.


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Not sure about that event. Gearing up for Barber. The Beemer is most likely Spring away, or January at the earliest. The plan is to do some swapping for BMW parts at Barber and dig in over the winter with taking the motor down for maintenance.
 
deviant said:
Not sure about that event. Gearing up for Barber. The Beemer is most likely Spring away, or January at the earliest. The plan is to do some swapping for BMW parts at Barber and dig in over the winter with taking the motor down for maintenance.
I'm about a 55 minute ride or so from Wilmington but it's not bad cruising. If you need a place to stay let me know.


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Jebus. That's probably what I need to do with the 550. I replaced the stator so I should probably do the field coil as well and all the wiring you mentioned when I redo the wiring. Dammed electrons.
 
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