TOPIC:

I have a 750 twin, that I am completely stumped on the charging system. I had a bad regulator and rectifier (it's the old style separate units) Replaced them with parts from Oregon Motorcycle Parts, and my stator had one leg that was suspect, so I went ahead and got a used, good testing stator and field coil to replace them. Now With the regulator and rectifier hooked up as per the wiring diagram, I see 14.5v form 1500 rpm to the redline everywhere except at the battery. I can go from Battery + to any bolt on the frame or engine and see 14.5, but across the terminals I only see 11.8-12.3~4 at any time. The negative battery cable was then suspect so I replaced it with a new cable, and I have tried changing to different bolts (with the frame of the bike cleaned underneath to bare metal) and at that bolt I get my 14.5 but not at the battery. I am utterly stumped I'm thinking there is resistance but I have no idea where to start to look even Thanks in advance...Chad

So, you're saying that if you check between the + battery terminal and the attaching bolt at the end of the negative cable, you get 14.5 volts, but if you check between the + battery terminal and the negative battery terminal you are getting a lower voltage?

Either the negative cable is bad, or you are not getting a good connection with your meter probe on the negative terminal, or the connection of the negative cable at the battery has resistance (if you are checking the terminal and not the cable).

Check cable to cable, terminal to terminal, and cable to terminal (both ways) positive to negative.

That is exactly what I'm saying. I've replaced the negative cable, the new one shows 0 ohms resistance, I've checked from the terminal to the bolt and get zero ohms, have I do show a voltage drop while running (did not check for resistance) of almost 1 volt. I do not have any idea what to do, I've replace the pos. and neg. cables, cleaned the ground point thoroughly and even changed the point where the cable grounds to (to the motor mount bolt in front of the rear master cylinder). All the contacts from the rectifier are clean and the connected to the original positions and I'm just lost. I've been battling this forever and I'm probably over looking something stupid, but I'll never give up because I love this bike so much In fact I'm going to look for new tires tomorrow and need to source out a new exhaust sometime soon. (Rusty chrome isn't cool apparently ) --Chad

Ride it

If the battery goes flat over time then we'll discuss it


When the turn signals stop working, head for the barn, that means the battery is almost flat and it's not going to run much longer. Mine started missing badly under load after the signals quit working. Got me home though.

There's a good possibility that you're chasing ghosts, so just ignore it till an actual problem develops.

As long as there is enough power in the battery to operate the electric starter, there'll be enough power to take you several miles (at least 15 miles after the starter no longer cranked in my case).

On the 78-80 750 twins, if you leave the small ground wire disconnected after replacing the battery, it will not charge. That's how I know

No electric start anymore... the starter clutch problems scares the crap out of me... no wire from the solenoid to the starter... the small ground wire from the wiring harness that happens to be near the battery? I had that hooked to the neg. terminal until today when I was searching my problems out. I will reconnect tomorrow, even if it's not the same on the 77's can never hurt having too many grounds I guess .I will try to find time in the next few days to take a nice long ride and try to figure out if it will go flat. Who knows? I once spent 6 months trying to find the problem with a Honda accord that over heats, only to figure out after all my sensors were replaced, radiator was flushed , fans pulled out and tested etc etc etc that my gauge had too much resistance in the connector behind it and every time the interior of the car got too hot the gauge messed up and went nuts, even when the temp of the engine was verified with a thermometer, replaced the gauge and presto "problem" fixed.... And I do ride it almost everyday to work and where ever I can, just been throwing it on my maintenance charger every 2 days or so...
--Chad

I was scared of the starter clutch originally, but on the 750 B's it's not that bad at all. All I did was get new springs and rollers and I was fine. Wasn't hard to get to and only took about 2 hours total. Now of course a year later I think my starters taken a dive. Time to look at that!

Good luck!

I don't understand the thing about being scared of the electric starter clutch on the 750 twins.
As far as I can see, the absolutely worst thing that can happen is some damage inside the cover, so you'd have to replace some parts.

The starter clutch fits around the crank, so it can't come off (at least not without breaking the crank), and if the mounting bolts shear it will just spin, since there's not enough room for it to move around.

I know there is one member here that is totally paranoid about the 750 twin starter clutch, but like I said, I don't understand why.

I'm not really super paranoid about it breaking... I just don't see a need for me to buy a new starter clutch "housing" (the things the rollers and such go in to) Because mine was cracked from when the bolts sheared off in the PO's care. I just pulled the springs and rollers, etc out of it and the housing is still there and when I pulled the engine out over the winter to paint the frame I just decided since I don't use the starter anyway why even put the big ugly cable back on for it. Plus Kicking is Cool . Still haven't got my long ride in, just back and forth to work (stupid hours make for little riding). On the good news my tires will be here friday so I'll be in for a new adventure.

As far as I can see, there are three good reasons for removing the starter clutch and starter.

Weight removal.
Because it's broke and you don't want to spend the $$ to fix it.
Because it's cool to have a kickstart only bike.

To me, those are valid reasons

Well if I could find a plug to fill the hole where the starter was I might just rid of it too, mostly because it's just sitting at the front of my engine being heavy. Might have to check with the local machinist to see if he can make me one. Hopefully I can get my tires on DIY style (I mount car tires and various other types of tires at work everyday)
Overall enjoying this year's riding season and If I get my twin as roadworthy as I want I might take my license test this year....(Had an Indiana Permit for two years) Still Looking for an exhaust though (got a 2 into 2 on it that has very rusty cans and a hole in a bottom of the left header pipe that has the left carb temporarily set to run richer than the right )Also need to get my oil and neutral lights working again...Kinda unnerving to have o idea if I loose pressure....Neutral is easy enough to find though. Bulbs are good...wires connected...just need to follow and check the wires now..

--Chad

GPzInfested (my Nephew) has been riding for at least a couple of years on a permit

Are you still in Indiana? If you're anywhere near Muncie you could stop in and maybe we could make you a plug (I kind of have a machine shop in my garage), I also have quite a few 750 twin parts left.

Live in Monticello, (you know Indiana beach and all it's the only thing anyone has ever heard of it for). Not really opposed to traveling towards Muncie (got a few friends who go to ball state). Always wanted to my own machine shop to play with ..LUCKY . It's pretty bad that when I was twelve years old I wanted a welder, a grinder and a Multimeter for my birthday and Christmas.... (got an awesome rc car lol...but the multimeter came soon...)

--Chad