She died.... And now won't start.

[SmashEmUp]

Finally got my project (81/C) running this past weekend after having basically a scrap bike in my garage for about a year. Was happy and proud. Rode it all weekend and yesterday, and she's been feeling damn good, no issues! Pulled the bike out of the garage and out to the edge of the driveway this morning, pulled the choke, started her up. After gathering my things and letting her warm up for maybe 5 minutes, I headed out. It was a little brisk this morning so I pulled over to put my little half face mask on for the hell of it about a half mile from the house. As soon as I stopped the bike cut out, like it wasn't warmed up yet and need the choke, but didn't have it. Pulled the choke and went to start it and it wouldn't even turn over!!! All the lights seem to be working okay and when I push the start button the headlight goes out (as I believe is should) and the oil and neutral lights dim like it is applying power to the starter but no click, still won't turn over. I was parked at a coffee shop right along the main road that local police officers frequent, so I locked up the bike and started walking back to the house because I was already late for work. This afternoon I go back, jump it. It cranks right up. But when close the choke I dies right out. So I jump it again and give it a little throttle, try to get it up to 4kish RPMs hoping to charge up the battery a little. I let off the throttle it doesn't even putter, just dies out. Every time.

Help me out guys! If I left out important, relevant info ask away.

Misinform away shiny!

[SmashEmUp]

Also, I did do a search before this post. Plenty of "won't start" or "won't crank" posts, didn't find one quite like mine.

[pat english]

im no expert,but i had something similar happen and it was my charging system...

[SmashEmUp]

Do you remember which component was your culprit? Just so I have an idea of where to start troubleshooting?

[shinyribs]

I think Pat is right about the charging system. I dont know about the DOHC bikes,but on my SOHC the headlight doesn't go off when you crank it. It will dim some,but still be burning. Charging issues are pretty common problems. Dont worry that your bike will not be reliable,it is, it's just that the age gets to them after all the years and they parts do wear out. If you have a meter you can jump your bike again and get it running. Check your voltage at the battery before you start the engine and while it is running. Get the rpms up to around 3,ooo + and see if your voltage reading goes up,and what your numbers are. Thats the best place to start. You might have to give the battery a good charge to have enough juice in there to keep the bike running first.

[SmashEmUp]

Sounds good.... If I remember correctly, on the DOHCs the headlight is supposed to cutout. Pressing the starter button actually changes contacts and not just closes one set. So in the normal position, one set of contacts are connected. Once pressed, those contacts are opened (I think directly related to the headlight) and the contacts to the solenoid are closed. Etc.... But....

I WILL DEFINITELY check the charging system. Thanks for the info guys!

[SmashEmUp]

Forgot to mention.... The bike already has a new battery and regulator/rectifier as far as electrical system components. I have my fingers crossed something else didn't knock them out again though.

[Re-run]

As shiny says, check the voltage at 3k rpm. But, how clean was the tank and the carbs? Refusing to idle like that could possibly indicate that crap got into the idle jets and they are plugged a bit.
If your voltage checks out, this is where I would go next.

[SmashEmUp]

Will do. Got it home yesterday after work, parked it, tried to do some research before digging in and wanted to get some input on here. I appreciate the help. Going to check voltage when I get home tonight. When I got the bike I checked the tank, and through inspection, the tank looked clean. I checked, no indication of rust or contaminants in the tank. Before I got it running I tore the carbs down, soaked and cleaned them, and rebuilt them with new jets, etc. The thing is, after it died yesterday it wouldn't even crank or turn over. I put it on the tender last night and it started right up this morning. So it SEEMS ( I am a novice at this stuff) that it's just an electrical problem. As I mentioned before it does have a new battery and voltage regulator/rectifier.

[seestheday]

For what it's worth, headlight on my 81K (DOHC) does not go out when I start it (it just dims).

Possible that it's not stock - but it looks like the starter and everything is stock.

[SmashEmUp]

Okay, good to know! I'll double check my stuff!

[SmashEmUp]

Shiny and Re-run... 11.8 volts at 3k RPMs. So..... Stator is shot?

[Re-run]

Maybe not, the amount of voltage is mostly controlled by the regulator.
I would do the tests on the stator and rotor listed in the manual but this sounds more regulator related.

[SmashEmUp]

Re-run: The reg/rec is pretty new (maybe about 250 miles). And I checked it today. All seems well with the reg/rec according the resistance checks per the manual.

[Re-run]

OK, next would be the tests on the stator and rotor then. But, I wonder about your wiring and the connections. It sounds like only 1 phase is charging. Go through the connectors, even if they look good, they can be loose if dirty.

Clean them up nice and shiny and make sure they contact each other tightly.

[Piute]

   Hey Smash
 Check yo safety switches,
                                     Clutch lever,neutral light,My switch went bad(removed),Also as mentioned I'm sure check yo plug connection on the ignition switch,(unplug look inside both are they clean(mine were rusted).
           There's so much to check and double check,hang in there you'll get it

    Oops check yo batt. level( my new went low some how )

[SmashEmUp]

Help me understand Piute.... How do safety swithes affect charging? Not arguing, just trying to understand. Trying to learn as I solve these problems. 

Sent from my iPhone

On Jul 27, 2012, at 9:28 AM, "Piute [via Honda CB750'S]" <[hidden email]> wrote:

   Hey Smash
 Check yo safety switches,
                                     Clutch lever,neutral light,My switch went bad(removed),Also as mentioned I'm sure check yo plug connection on the ignition switch,(unplug look inside both are they clean(mine were rusted).
           There's so much to check and double check,hang in there you'll get it

---

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[SmashEmUp]

Re-run: the rotor and stator checked "good" according to my resistance checks per the manual. I took them off anyway and am taking them to a local rebuilder to test and inspect them. The guy that answered the phone said he had a CB900 and therefore was very interested in helping me dove my problem. 👍 we'll see how it goes.

[Piute]

SmashEmUp wrote

Help me understand Piute.... How do safety swithes affect charging? Not arguing, just trying to understand. Trying to learn as I solve these problems.
>    Hey Smash
>  Check yo safety switches,
>                                      Clutch lever,neutral light,My switch went bad(removed),Also as mentioned I'm sure check yo plug connection on the ignition switch,(unplug look inside both are they clean(mine were rusted).
>            There's so much to check and double check,hang in there you'll get it
>      

                      YOUR HEADING reads

                                              " She died.... And now won't start."

       Trying to help ,
you take the the good and apply,hell with the rest,ME if it already applyed ,you checked al(ign.plug,wire's from switches)that right ?

[SmashEmUp]

You're right..... My bad! Sorry man, that was the initial problem. But after that was resolved, another problem persists. Basically, the bike died. Apparently the battery was so dead it wouldn't turn over, not even click. Got it home, put it on the tender over night and it started right up. Went back and checked. No charging voltage. Charging system is kaput at the moment.

Sent from my iPhone

On Jul 27, 2012, at 1:23 PM, "Piute [via Honda CB750'S]" <[hidden email]> wrote:

SmashEmUp wrote

Help me understand Piute.... How do safety swithes affect charging? Not arguing, just trying to understand. Trying to learn as I solve these problems.
>    Hey Smash
>  Check yo safety switches,
>                                      Clutch lever,neutral light,My switch went bad(removed),Also as mentioned I'm sure check yo plug connection on the ignition switch,(unplug look inside both are they clean(mine were rusted).
>            There's so much to check and double check,hang in there you'll get it
>      

                      YOUR HEADING reads

                                              " She died.... And now won't start."

       Trying to help ,
you take the the good and apply,hell with the rest,ME if it already applyed ,you checked that right ?

---

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NAML