Carb won't stay on the bike!!! UPDATED 3/6 Video (they stay on)

[wladziu]

He pulled the head?  I thought he just popped the cover. 



I third the cam timing.  Motion carried. 

[ke7syv]

I fourth the Cam Timing. I would give thought to Wladziu's idea about fuel pressure. When I saw the video it was the first thing I thought of. I remember how picky the Weber on my 84 Pulsar NX ca e about fuel pressure. Maybe something with at least 1 gallon of fuel would be my recommendation. Hope this helps. Smart thinking, posting the vid and all. 

[thousandlegs]

We have had the engine apart down to the block.  The timing is spot on but if I can't get it figured out I'll probably take the valve cover off again to quadruple check.  In fact, I'll probably do that tomorrow.  Today I took the carbs apart and cleaned them very very thoroughly and put in some 228 mains.  They look like new carbs now inside and out. 

Something that puzzles me is that there seems to be no difference with the choke open or closed.  There hasn't been any timing advance work done.  It is set at the standard setting. 

Do any of you live near Pensacola, FL so that maybe we can swap carbs just to test? 

[coll0412]

Check the cam timing, and post a picture of what the cam settings are.

I really doubt it is your carbs, but if you spray in a little fuel it should rev right up if it were the carbs.

[thousandlegs]

Check the cam timing, and post a picture of what the cam settings are.

I really doubt it is your carbs, but if you spray in a little fuel it should rev right up if it were the carbs.

I agree that it SHOULD rev when spraying in fuel but it doesn't.

[wladziu]

I haven't seen the the timing setup on my bike, but it's a common mistake on cages to set the sprockets on the wrong stroke.  Hel1, you know what we're talking about.  Like it's "180 out".  Very easy to do.
Yes, it's firing, but it could be just from compression and hot plugs.  Like a diesel.  And you've got to admit that that motor sounds like crap.  Would explain why it's only idling (if you can call it that) on full throttle: more fuel to be compressed. 
Or not. 


Maybe the head gasket is still laying on a shelf somewhere.  It's been known to happen.  But, you're not pinging and the compression is alright (except for the slight loss on the left). 
You could try bypassing the petcock.  Don't think it would do anything, though. 

But, if your cam timing is dead on (after you've verified), your carb settings and air management are stock and unfouled, your plugs are new and gapped and firing, and your valves are adjusted, then you may have quite a mess on your hands.  Your coils may not be getting enough or putting out enough juice, but not likely.  Those things usually just fail outright, and I hear the ones on the GS are pretty reliable. 
One would assume terrible blow-by or more dramatic problems with a rod, but the compression doesn't seem THAT unusual.  No banging or anything. 

Run some seafoam to clean out any junk on the valves and hopefully improve the compression,  and maybe try a new tank of gas instead of that old stuff with water in it. 
Other than that and the timing:   

[thousandlegs]

Ok, for those who are following this problem here's the solution:

Some deep searching and, thank you Kerry, I found an old thread where you had to replace the black four wire connector from the left side under the fairing.  I cranked the bike, jiggled that connector and the idle shot up and it was running strong.  I cut the connectors off and connected the wires with blue butt connectors and some dielectric grease...the bike runs fantastic now.

Also, in investigating I found that the cams were one tooth off of rotation and the compression is now L155 R170.  So, all you "running on one cylinder" people, check that connector.

Thanks everyone!

[wladziu]

See!  The old guys let you rack your brain, sounding like an idiot.  Then they jump in at the last minute with a simple thing like a friggin butt connector. 
With their dam 800 years of experience.


Somebody should put that stupid thing in the wiki.  Four pages for a flipping connector. 

Glad it worked out for you, anyway.   

[5thAve]

Congrats.  Glad you didn't sell it after all! Enjoy.

[utgunslinger13]

WOW!  Something so simple and you were ready to give up!  I'm glad you stuck with it and were able to find out the problem!  Happy Riding!

[the mole]

You did well to get to the bottom of that, it would be enough to drive anyone nuts! 

[thousandlegs]

You did well to get to the bottom of that, it would be enough to drive anyone nuts! 

It was a short drive.  At any rate, it runs great

[wladziu]

Oh, I see now, you found it in an OLD thread.  That's an awesome use of the search function! 

Guess I should check the connector on mine before it sh!ts the bed, too...

[bill14224]

Glad you finally found the problems.  You had three problems going on at the same time, that's why we were so flummoxed! 

[thousandlegs]

Glad you finally found the problems.  You had three problems going on at the same time, that's why we were so flummoxed! 

Well, the real problem...the one that was causing the most trouble, was the connector.  I had no idea that an electrical problem could manifest itself that way.

[Suzuki Stevo]

Well, the real problem...the one that was causing the most trouble, was the connector.  I had no idea that an electrical problem could manifest itself that way.

I thought that your initial problem was  "Carb won't stay on the bike!!!" Where your intake valves open when they should have been closed (cam timing problem) and maybe that was the reason your carbs where popping off? Wouldn't that make the electrical problem secondary?

[thousandlegs]

Well, the real problem...the one that was causing the most trouble, was the connector.  I had no idea that an electrical problem could manifest itself that way.

I thought that your initial problem was  "Carb won't stay on the bike!!!" Where your intake valves open when they should have been closed (cam timing problem) and maybe that was the reason your carbs where popping off? Wouldn't that make the electrical problem secondary?

Yes, but only secondary to the original problem.  The carbs popping off was solved and rather than opening a new thread I just continued with the troubleshooting until the entire set of problems were solved.  After the cam position was solved the issue of running on one cylinder was the gremlin at hand.

[bill14224]

It was running on one cylinder because that connector carries power from your ignition kill switch to the coils, and obviously (NOW!) one coil wasn't getting juice.  The dreaded orange and orange/white wires come into play again!

If you had checked the plug when the cylinder was dead, you would have found no spark.  Then we would have told you to make sure you're getting power from the kill switch to the coil, and a good connection from the coil to the plug.

This is a good example of why it's important (not to mention time and money saving) to diagnose problems properly rather than take a shotgun approach.

[thousandlegs]

It was running on one cylinder because that connector carries power from your ignition kill switch to the coils, and obviously (NOW!) one coil wasn't getting juice.  The dreaded orange and orange/white wires come into play again!

If you had checked the plug when the cylinder was dead, you would have found no spark.  Then we would have told you to make sure you're getting power from the kill switch to the coil, and a good connection from the coil to the plug.

This is a good example of why it's important (not to mention time and money saving) to diagnose problems properly rather than take a shotgun approach.

That is not necessarily the case.  When the cylinder was dead there was a strong spark at both plugs but apparently not enough to spark under compression.  I gave ALL symptoms as I discovered them and there WAS spark on both plugs.