Bike not running after replacing the R/R

[scout127]

After my '83 gs850's r/r fried, I replaced it with a new one. Now the bike will not idle or rev as smoothly as it did before. To the point that it is un-drivable. Also, the headlight flickers (it didn't do this before the new r/r), and the # 3 cylinder doesn't seem to be hitting.

I have a good spark on all plugs and fuel in my bowls. None of these problems existed before the r/r fried. Could there be other electrical problems I'm not aware of? Where would you start?

(You should know that the bike sat for about 3 weeks before I was able to put the new r/r on it...not sure if this would be a factor).

thanks for any help,

nh

[fenderfreek]

What kind of R/R did you use? A faulty R/R can also ruin a good stator - have you checked that out?

[Speedo]

Suck it up, pull up Stator Papers IV (on this site), grab a multimeter (a beer and a buddy), and go through all the tests. I'm still going thru a similar nightmare but making good progress finally. Ref my posts "Stator Paper Caper..." current, and "GS750 ran great, now like crap" from a few weeks back. Both in TECH forum. Hope it helps....I feel for you.

[BassCliff]

Hi,

Yes, indeed! The Stator Papers are your friend. Connect the ground wire from your r/r directly to the negative post of your battery terminal. Clean every electrical connection and ground on the entire wiring harness, including the fusebox and ignition switch. If your r/r has a "sense" wire, be sure it is connected to a switched 12v source, usually the brake light at the brake light switch.

I would guess that your stator is bad too. But clean your harness and run the tests first to be sure. Keep us informed.


Thank you for your indulgence,

BassCliff

[scout127]

I cleaned my connections and checked my grounds. Then I started the tests as found in "The Stator Papers IV". My bike passed the first test, which according to the "Papers" means that my charging system is OK.

The bike still runs like crap. I had a hard time getting it to rev to 5000 rpm in order to do the first test. Might there still be a problem related to when my r/r fried, or should I be looking for something totally unrelated?

out of ideas,

[Buster-boy]

I had similar issues - too many to list actually - even after a new stator and R/R. Turns out a carb synch was all it needed. Not sure how it was related, but it worked. Go figure. Believe me when I tell you though - don't take my word for it. I'm a schlub compared to these guys. All I know is it worked. :P

Listen to Basscliff and all the others here though. They're GODS! They've been there, done that, doin it tomorrow a thousand times over.

Jim

[apcsox]

sounds like the same issue I had when my carbs fell out of synch and needed to be rebuilt

I cleaned my connections and checked my grounds. Then I started the tests as found in "The Stator Papers IV". My bike passed the first test, which according to the "Papers" means that my charging system is OK.

The bike still runs like crap. I had a hard time getting it to rev to 5000 rpm in order to do the first test. Might there still be a problem related to when my r/r fried, or should I be looking for something totally unrelated?

out of ideas,

[Speedo]

i agree w busterboy - listen to these guys, most of 'em really are 'gods'.

if ur bike passed StatorPapers IV test 1, then (lucky you), at least your charging system is ok and you can eliminate that.

But even if you have problems with the charging sys as I have had for many many years, the bike still ran fantastic right up until it "ate" another battery due to charging sys. So, given the past two givens, the fact that yours runs like crap now probably has nothing to do with charging sys.

So now you have to check:
1. Spark. Have you done the volts to coils test (on BassCliff's site, maybe here to). What ignition sys are you running? Stock? Dnya?

2. Are you sure you are getting good spark to all 4 cylinders? Start pulling plug wires while bike is running to see if it makes a difference (if u pull a wire and it makes 0 diff, that means that cylinder is not firing).

3. After that, remove each plug, hook up to wire, ground against head, and crank starter. You should see a FAT BLUE spark every time. Test them and tell us

4. "Crap" you say it runs like. Let's define that better for us to help us help you. Badly on all 4 cyl? running on 3? running on 2 (yes they will run on 2 - I've broken a set of points on my prev 78 gs750 and i still got home)?

5. If it's not a spark thing, 99% its gotta be a fuel/fuel delivery thing (again, nevermind the charging thing...if you have a good fully charged battery the bike will run fine despite a bad charging sys....for a while that is...maybe 50-100mi...but hope u get my point).

Let us know, we'll try to help.

[Speedo]

ps Not to diss Apcsox but if the carbs are out of sync (and they could well be) that does not necessarily mean the carbs need to be rebuilt. There are well documented procedures and proper tools you need to synch carbs(how would you like to brag to your buds about using a "MANometer?"). Not trivial stuff but MUCH easier to do than any other carb rebuild / check float levels / blah blah blah all that complicated black magic carb stuff. Trust me, if "I" can do it (and I can and have), YOU can do it as far as carb synching.

pps Carb's out of synch shouldn't make bike "run like crap", just not as good as before, so I'm guessing there is something else going on. Tell up about your carbs, work done to them, gas tank/work done, etc.

[scout127]

By "crap", I meant that it wouldn't rev smoothly (or very high), and when I put it in gear and eased off the clutch, it would go dead (not running well enough to take a load). I have good spark and voltage to the coils.

I finally got the bike running better...no longer like "crap". I am beginning to think that I should re-sync the carbs (I synced them using my home-made baby-bottle and rubber stopper device...looks a little like drug paraphernalia).

I played will the throttle a little bit and finally got the bike to rev like I wanted. I will sync again, but I still don't understand how they can "fall out of sync". Would the bike sitting for about a month cause this?

Thanks for the help guys. I am just glad I didn't have to buy a stator!

[fenderfreek]

Just sitting wouldn't do it, but if you didn't tighten the lock nut enough, or if you moved the adjuster while tightening the lock nut, your sync could be out of whack even though you just did it.