i'm gonna melt this bike to iron bars and then eat them bit by bit in my salad

[gsdox]

well after owning the bike for about 8 months, i haven't been able to drive/use it like a proper human being. When i bought it it went like devil's crippled mother, with one cylinder stuttering, hanging idle and not doing what it iwas supposed to. The po said it's been left for a year, the carbs need cleaning. ok i said, since i bought it relatively cheap (not that 400e for a 87000km 91' gs were so cheap) i didn't mind doing a carb clean-up. I did that and then it wouldn't fire up. (first thread in here, then). After hearing all the advices, doing a second and a third clean up with the help of the neighbours, the bike did fire up and i was happy as a clown, since it sounded almost healthy (no stuttering and stuff). After week or so I took the bike for a longer ride, and I had an idle hanging again, then back to stuttering with the one cylinder on and off and finally it dropped dead (actually couldn't keep going on one cylinder) 15km from home (second thread in here, then). After going to the spot to remove the carb, reclean it - nothing - going back to check the coils - in specs - and briefly failing for a week to fix it right were it was, I had it brought home. After many many hours fiddling around with it, i got it to start. Apparently it had been a fuel filter not providing much petrol to the carbs, or the fact that the fuel tank had a small amount of gas - it wasn't full (or so i thought and it was just a sign of His holiness).

Well the bike did fire up and that same day would fire up each time i tried, but it would work poorly, stuttering, hanging idle and the good old story. I read the other half of this marvelous forum's threads and i considered these: Perhaps i should change the oil and the oil filter (I knew that couldn't possibly be the solution but i was planning to either way, and sometimes hope does die last) but what was my temple of belief was adjusting the valves. I did the first the same day (I already had a filter sitting). Afterwards I fired it up and it was all the same (surprise!). Ok I said, it needs a valve adjustment.
While getting all the gear for that operation and finally doing it I read in here about a small little black cap on top of each carb whose absence might cause hanging idle. Well since I had one missing (yeah! Another temple of hope and belief) I thought that could also be the source of my problems. I completed the valve adjustment, found something to cap the carb and tried to fire it up with all my efforts, sweat, and hopes concentrated on that moment.

Now what do you think, would that bike fire up? Would that bloody, shitty f%$king bike fire up?
No sir, it definitely wouldn't.

Now what's the deal/what i have tried so far:
1.The oil/oil filter is new
2.The valves are in specs
3.There's a small cap on each carb (and even when i take it out it's all the same again)
4.The coils give spark
5.The spark plugs are new
6.Even if the battery is no good, i jump start it wired to the car's battery, so the spark should be healthy
7.The tank is full
8.Both carb bowls have fuel
9.The float height seems good
10.The carbs are clean
10.The
11.Even if 7,8,9 or 10 were the issue, the bike won't start even when i drip gas right to the air intakes of the carbs. The previous time i couldn't start the bike (when i finally got it working with the help of my neighbours to properly clean the carbs) that trick would make the bike fire for a couple of seconds. Now it does nothing.
11.It seems to have compression but I'm not sure as i have no tools to measure it. Could that alone be the issue since I had the bike running sometimes as you have read?

One hint: when i crank the engine i use the choke (it's about 5-10 degrees C here). If I crank the engine without it the noise of the spinning is flat, the same again and again. When i pull the choke I hear from time to time (say every 4 spins) a sound like the engine is going to fire up, you know, like when it gets compression and it fires up, giving fumes to the exhaust. And if i leave the choke and after a while get it back on, the next spin (the first with the choke on) will be a spin like that, sounding as i have described. But even if it sound like it's gonna start, it won't, however hard i abuse the ignition.

Any help greatly, greatly appreciated!

[sledge]

I once had one pass through my hands that had a constant misfire and would drop a cylinder from time to time. Eventually tracked it down to the reg/rect earth. Look at the battery` -` terminal and follow the black lead away from the battery, 2-3 inches along is a spade connecter, make sure its clean and tight......it worked for me 

The easy way to check for poor earths is to connect a jump-lead between the `-` terminal and a clean metalic point anywhere on the bike. If the problem goes away you have got a bad earth.......somewhere.

[ver4]

Welcome to my world.

[BeerGarage]

gsdox

Is it very cold where you are?  Have the carbs been rejetted?  I have heard that the stock jets can be so lean that the bike just will not start below 45 F. 

Do you have stock air intake?
Do you have stock exhaust?
Do you have a carb diagram to check if all the parts are there and all the hoses are routed correctly?
Do the carbs have the o rings under the plastic caps?
Are the air hoses old and cracked?
Have you tried a clear plastic hose attached to the carb float bowls to check the level and be sure there is gas in each one?

good luck.

[redhenracing2]

Mine ran on one cylinder below 6k, so I had to always keep it a little revved if I didn't want my gas mileage to go down the drain. Not that that helps you any, just know that you don't have the only gs with the devil in it.

[the mole]

The most basic thing a motor needs is good compression. So far you have done a lot of work to it, but haven't checked the compression. You say the valves are 'in spec', does this mean the valve seats and faces are good, or just that the clearances are OK?
A compression test would not cost much to have done, or for not much more you could buy a cheap tester and have one to use on other vehicles.
How about doing a test and getting back to us, as that would eliminate one way or the other a major question mark about your bike.
Good luck.

[Twisted]

If you do melt this bike to iron bars and then eat them bit by bit in your salad could you please post pics 

[the mole]

^ I wonder why he's called "twisted"?

[gsdox]

Thank you all for your suggestions!

@sledge: I'm jumpstarting the bike, so the -pole of the cars battery goes through a jumper cable to  metallic part of the bike (i prefer the foot gear change lever). I think that should be sth like the easy way to check you suggested. Please tell me if I'm wrong and need to check again.

@ver4: If you 're thinking of eating your bike as well, i have a good recipe!

@BeerGarage: It's somewhere like 45F now but it's the colder period of the year. The bike is all stock and the carbs are not rejetted. I have the manual diagram and i think everything's ok. Consider i pour gas from the intakes and it doesn't fire up. There are o-rings under the caps, the air hoses are good, the carb float bowls are full (tried the thing with the clear hose).

@redhenracing2: Good luck dear fellow, do you think an exorcism would help us?

@the mole: I'm seriously thinking of buying a cheap compression tester (i found one with pieces with these specs: 10x1.0, 12x1.25, 14x1.25, 18x1.5, do you think it's suitable for the bike's spark plugs?) as i can't move the bike to have it tested. As for the valve clearances, i checked them, both intake and the right exhaust one were out of specs (very tight) and i  got thinner shims. Now all of them are in specs. Just that, I don't know if the valve seats and faces are good, i didn't check that (i just spotted it on the haynes manual and it's not a job I'd confident to do).

[the mole]

Thank you all for your suggestions!

@sledge: I'm jumpstarting the bike, so the -pole of the cars battery goes through a jumper cable to  metallic part of the bike (i prefer the foot gear change lever).

Well I hope the high current you're putting through the gear pedal doesn't end up welding it to something in the case or gearbox. I would NOT be using any sort of moving part as the earth point. Just connect to the battery terminal or some part of the engine case or engine mount bolt.

[tdiloren]

   My wrenching skills are limited so I start with the basics. You checked the fuel and spark but I didn't read anything about air. Check the air filter or just pull it and see if it starts. I've also read on hear that these bikes seem prone to vacuum leaks that cause some of your problems. Check/Replace the lines

[tb0lt]

Just an idea....check your cam chain tensioner for proper operation and also check your cam timing while you are at it. I've seen engines act completely weird when the chain isn't tensioned right or when the timing is off by one tooth. Also, get a compression tester. They cost under $25 at most places and are worth their weight in gold. With compression numbers in hand, you will have a better picture of WTH is going on with the engine and it will help narrow things down. I agree with the person who suggested checking the ground wire... the bike goes nuts when that wire is loose.


PS:As for using ground points instead of the -ve on the battery itself for jump starting, I believe it is a BS theory. I've dealt with a mix of different vehicles including truck-to-motorcycle jumps with the batteries directly connected -ve to -ve and +ve to +ve and nothing ever blew up and no damage was done. As long as you have a properly working charging/regulator circuit on the running vehicle, you should be fine.

[ver4]

I have a thread somewhere where it listed all the things I had checked over on my bike to fix it.

[Adfalchius]

PS:As for using ground points instead of the -ve on the battery itself for jump starting, I believe it is a BS theory. I've dealt with a mix of different vehicles including truck-to-motorcycle jumps with the batteries directly connected -ve to -ve and +ve to +ve and nothing ever blew up and no damage was done. As long as you have a properly working charging/regulator circuit on the running vehicle, you should be fine.

I believe the reason they tell you not to connect directly to the battery is to prevent any hydrogen gas that may be present from being ignited by a spark.

[sledge]

PS:As for using ground points instead of the -ve on the battery itself for jump starting, I believe it is a BS theory. I've dealt with a mix of different vehicles including truck-to-motorcycle jumps with the batteries directly connected -ve to -ve and +ve to +ve and nothing ever blew up and no damage was done. As long as you have a properly working charging/regulator circuit on the running vehicle, you should be fine.

So we can assume you have yet to come across a bike or any other vehicle with a poor or high-resistance connection from the battery to the frame then? 

This is a fault finding exercise, if that black lead from the battery is loose or dirty where it bolts to the metalwork you can try jump starting from a supertanker and it wont go 

[bigfatcat]

GSDOX, if it were me, I'd be troubleshooting for an ignition fault, considering all that you've done so far and the symptoms, even though your #4 says you see spark (while cranking with the plugs out i'd guess), and assuming you know you have compression ...

For instance a  failing igniter can give some of the symptoms you describe.

[twinrat]

i had a similar problem on a second hand vehicle i brought ,the fellow told me that if didn't get it started first thing in the morning it wouldn't start all day .the problem was somebody put the condenser to earth .changed it around ran perfectly.Another possibility is the wire from the points is crimped too hard and is sheared under the plastic to the lug these suggestions are only applicable to older vehicles with points, i had these problems happen to me years ago.. good luck with what ever you find..

[gsdox]

thanks again all of you guys for your interest and suggestions! You are truly very helpful (not only now but at my previous posts as well).

I'll try to see the earth-thing again. If i have understood correctly, I should Connect car+ to bike+ and car- to an earth point that is preferably a bolt on the bike's engine. If the bike's problem is only this faulty earth, the above connection will solve/bypass it right? And therefore it should work, right? Sorry for being a geek, but i want to be sure that i got everything clear...

Another thing: When i adjusted the valves, i did it without the special tool, just like mark on gstwin.com did it, by removing the camshafts (and necessarily by removing the chain tensioner too) . Then i put them back on but I missed a tooth on the chain, so when i cranked, it did a clong-noise. I fixed it by trying to get the notches on the camshafts face each other at the coil's p/t point. I put the chain tensioner back in (pretty stiff) and then all sounded fine. But couldn't work/start/fire up of course!!!
So with the noises facing each other, the valves with good clearance and a new gasket, is there sth i might have screwed up at this operation? Sth to look at?

Another thing: the compression meter i decribed earlier with specs: 10x1.0, 12x1.25, 14x1.25, 18x1.5 will fit the bike's spark plugs size (i just don't know what this sizes refer to / how to relate them to the ngk dp8ea-9 specs, which i don't have)??

And last but (perhaps) most important: When I say the bike gives spark, i mean i can feel it at my finger. I cannot actually see the spark with my eyes (I'm not blind though), if that's what you mean when you talk of spark. I just take the connected spark plug out  and crank the engine. I don't see anything (I have done this at night too) but i put my finger and feel a little shock. That goes for both spark plugs, and is the same if the bike is jumpstarted or normally ignited. If I should see a spark, and what i get is just a weak spark, please say so

Thanks again guys!

[The Buddha]

Well it will melt mostly into aluminum ... but I guess I ahve to read it to post ... 1 sec.


Cool.
Buddha.

[The Buddha]

5.The spark plugs are new

The story mimics my story with ginovega's bike. It sat in my garage for a week. The short story is this. I went to his house and we did a jet job. The bike ran just fine with the obvious rather quiet cadence of a stock pipe. I left and gino proceeded to change the oil and filter, and fit his V&H pipe. The bike was jetted for the pipe, it actually ran a bit rich with the stock pipe. Then it refused to start. He tried for a few days, then carted it over to my house.
I busted my butt, knuckles and head on it till one fine day I pulled the spark plugs out - they looked nice and shiny and in an attempt to read em put in old ones off my bike. Kaboom, first try it starts and runs like a champ. I should ahve charged gino 70,000 lbs of gold. That clown did not tell me he changed the plugs too.

You my friend are suffering from that same thing. However did you swap the plugs after it ran last ? if so that is the culprit.
If not, I got no idea.

Cool.
Buddha.