So I recently finished my several month rebuild of an old crusty 1974 CB750k4 and took it for an epic failure of a maiden voyage. I'll try to make this interesting for everyone viewing as someone is inevitably sitting there laughing, knowing all of the problems.
In any case, I bought this bike from a guy here in FL who was the only owner and reassured me that the bike was in great shape and just needed a new tube in the rear tire and a master cylinder rebuild to be road worthy..HA. ha.
I ended up finding mouse poop under the busted starter motor (no lie), replaced the whole wire harness from the corroded mess that was in "good shape", installed a new headlight bulb, new tail light assembly and turn signals, all with new fuses, rebuilt the front forks with new seals & 7.3oz of new fork oil, new tapered stem bearings, rebuilt the master cylinder & caliper, cleaned all the electrical switches, installed a new starter motor and a momentary button from the shack (yes the 1.5amp at 125vac normally open works great), rebuilt the carbs with 125 main jets and installed 39mm pods, de rusted the inside of the tank and rebuilt the petcock, among much paint and cosmetic work.
So after all this, I start it up... she purs man... she purs. Right to 1000rpm with no hesitation on the first kick. Just sitting there in the garage. But I notice the tail light and head light don't come on with the switch- just the front turn signals.
I took it around the block and it ran great. I get home and take the brown/red wire from the switch assembly on the bars and tap it to the brown/white (for switch control) run a second wire off the brown/red and ran it to the solid brown (tail light). All electronics work fine. I put the turn signals on with no problem, try it again and the 5amp tail light fuse blows. But it kills all the power to the entire bike with the headlight fuse and main fuse in tact. I try again another day and I get to the corner of my development when it dies. Luckily I had some spare fuses so I pop a 15amp in just to get to the gas station. And then, as I am on a busy 55mph road, the bike starts to lose power. I assumed it was because I only had 1 gallon of gas so I throw it in reserve, start it back up and she goes on... only to lose power at high rpm again and slowly but surely cut off over about 1/4 mile.
This time there isn't enough power to start the bike with the button so I kick it, turn the idle screw to 3000rpm and made it home with it cutting out only twice on the 2 mile ride back home. When I got home I didn't have enough juice to start it, turn on the turn signals or honk the horn.
So, what gives? I thoroughly read the wiring diagram and other posts. I haven't seen someone with such light issues but I will admit that the brown/red does not run one of the two brown/red (with white tape around the top) from the new harness, as it previously did when the tail light didn't work with the old corroded ones.. Would tapping a third wire off the brown red and connecting it solve this perhaps? Also why am I cutting out? Would it be the jet size is too small? Could it be that I am not getting enough power from a charging issue to get the engine to spark right? Please help. I have had enough nights drinking beer staring at this until the answer comes.
oh, and why is my front tire bouncy like I am on a dirt road or something?
