Bowl levels are the same, sooooo.....

[Scud]

Ace, Bert and Keith...Thanks.

Scud

[gsBert]

here's a good plug chart to look at because if you click a plug it magnifies it really well:

http://www.dansmc.com/spark_plugs/spark_plugs_catalog.html

anything numbered in blue is fine, scud, your plug looks like #22 doesnt it?

keith:
i never assumed his carbs are all jetted right, matter of fact, i keep telling the lazy no good smurf to takem apart so he can check. (ya reading this scud? lol) i bet his needle in #1 is 1 notch lower, the main is 2.5 smaller or the pilot jet is a 36 instead of a 40 or the mixture screw is in 1/8th of a turn more or something obvious like that.

keith is really right to not trust you when you say the bike is running fine though. he makes a very good point. im a good example of that, not knowing much of anything, i thought my 1150 was running fine when i first got it until i tried opening it wide up and all i got was a burp and too much gas, thsi took me a whole year to finally solve (just in time for soemthing else to go wrong with the bike)

[Anonymous]

Keith, I suspect that adjusting valve lash won't provide any clues or difference since his compression is consistant indicating no hanging valves. I also don't believe that the #1 plug showing a lack of combustion will be affected by jetting since it is not showing signs of combustion. Not lean, not correct, not rich... I think the most logical thing to do would be to warm the bike and measure the temperature on each exhaust head pipe right by the combustion chamber to determine for sure if combustion is occuring. It makes me nervous when neither compression checks, fuel checks and spark checks and a new plug fail to explain why the plug shows no signs of combustion. My only other thought is that the cylinder MAY be firing but only in a limited range or operation since the owner sees some signs of combustion on the plug... perhaps the pilot circuit is not supplying gas (or air) but the bike fires on that cylinder while running on the jet needle / main jet?

[gsBert]

he is seeing combustion. a plug coming out white as opposed to chocolate doesnt mean theres no combustion, it means the combustion temperature is at a heat range where the plug will turn white instead of tan.

if he had no combustion in one cylinder, the plug wouldnt come out clean, it would come out wet. in this case i'd say the engine will seize soon because all that unburnt gas is ending up in the crankcase, lol.
hey scud? you dont smell gas in your oil do you? :roll:

leave the poor guy alone and let him ride.
and anyways, whats the worst that can happen?
holing a piston is not gonna bring the bike to a screeching halt in the middle of a curve, and 16 valve gs 750 engines are 250 to 500$ in good working condiditon. (i'll come and help you put it in scud, since you'll need the help on acount of your carb-removal lazyness (jsut poking fun at ya, dont get defensive :twisted: )).

better yet: scud, stop letting us make you feel paranoid and ride the bike, if you hole a piston i'll give you my 750, all you got to do is pick it up. (put your carbs on it though, mine run a bit rich)

[jlmoulto]

****Please Use at own risk....From Someone who Can't get their own bike running correctly and definitely don't pretend to be a mechanic.*****

1980 GS850 Able to Wheelie no prob and maintain a top speed nearing 120mph on the speedo. Compression test revealed 140, 140, 140, 50 or something real close. No or little combusion on one cylinder. Even a mechanic did not realize it was only firing on three cylinders. Took a former GS850 rider to say...hmmm, this doesn't ride nearly as well as my GS850 used to, when we discovered a cold pipe on #3.

Based on my experience with the carbs on mine, I would tend to guess something is amiss in them. When a "real" mechanic looked at mine, he discovered that there were different jets in each carb for some reason and the settings were screwed up.

Something is not right. Simply using logic, it makes sense that we make all plugs look like the "clean" one or make the "clean" one look like the others. "One of these things is not like the other."

Ignoring the symptoms is akin to putting black tape over the warning lights on the dash of your car...doesn't fix the problem, but much less distracting while driving at night. Easy to give the ignore advice when it is not your bike. Let me see...a few dollars diagnosing the problem vs. weeks down and hundreds of dollars cause you just blew the engine?

[flyingace]

Keith - I took or meant no disrespect.

I think you hit the nail on the head - Scud needs to verify his bike is really running well and is symptom free.

Scud, I think you should consider riding a similar bike (known to run well) and compare it yours. Maybe you can find another GSer in your area? If you find your bike to be lacking power or has other funamental problems not seen on the other bike, the expert users will have a lot more to work with.

Ace.

[gsBert]

i agree.
scud: these people (me included) telling you to take your carbs apart and have a look are right.
but you only have 2 options:
a) you ride and forget until it goes boom (if ever)
b) you take the carbs apart and check the jetting

[Scud]

ok fellas....you talked me into it.....I will take tha carbs out...again...and let you know what I find, I mean everything, jets, needles I am not so sure of about those since I do not believe mine have them and if they do I have not monkeyed with them (she ran fine for three years before I did a carb dunk two years ago and I know I did touch any needles). Forgive me if I am missing the obvious and staighten me out (1980 TSCC model with CV Carbs....needles :? ).

Now...to answer a few questions.

Yes Bert, my plug does kinda look like number 22, thanks for the webpage!, and if anything, the rim has less carbon but the porcelain looks that white. I just took a minute to smell my oil (wife thinks I am a sick mother) and it does not have a fuel smell at all and the level in the window is the same it has been...at the full line. Thanks for the offer on the other bike, but I really, really like mine, in fact, I think I love her.

George, when I get on it at 55 in fourth she hauls A.. This tells me that all cylinders are firing and as mentioned before, she idles fantastic...hmm.

Ace, I live in a small town, no other GS bikes on the county, I am sure of that. If I stumble on one I will let you know, but as mentioned she runs like she did before the carb re-build two years ago or maybe even better?!?!

Keep the thoughts coming and I will investigate further when time presents itself.

Thanks again for everything.

Scud

[gsBert]

glad to hear you're finally getting over your fear of disassembling the carbs. its really no big deal, you get better at it every time. and yes your carbs have needles, adjustable ones at that...
use a hairdryer to heat up the airbox before reinstalling it, makes it easier (more pliable). i ask my girlfriend to do it for me she has more patience and curses less...

make sure to let us know what you find.

[KEITH KRAUSE]

OK. Just so you know where I'm coming from.
I went by the pic' he sent of the plug. The white insulator is nothing new to me, very common. It's the gold color of the plug outer rim that I'm focusing on. The rim looks as clean as the threads! 8O There's a shine. This plug has not been subjected to the same amount of heat as the others. His plug photo doesn't look like 22 on the chart. Yes, you could say the insulator is white, but there's still some carbon on the rim of 22, just like there's varying amounts of carbon on every single plug on that chart. Read back, that's why I say this plug is "burning" wrong. Carbon shows combustion. There was no carbon at all on his plug. So there's very little combustion going on. Maybe a little so he can feel the header get "hot", but not enough to build even a thin layer of carbon. I also think unburned fuel could be scouring the plug clean and is certainly keeping temperature down in the cylinder, further hindering combustion. That's all I've been saying all along. A plug that clean isn't acceptable, it's telling you somethings wrong.
Somethings missing in the triangle. He has decent compression according to his test. So that leaves a lack of fuel or a weak spark.
I'm sure there are some things he can start checking.
As for my valve clearance thought, I mentioned it because the clearances should be checked as normal maintenance anyway. I don't know about a "hanging" valve, but if the intake valve tappet clearance is too wide, the valve won't open far enough and it won't open long enough. If this is the case, how can the correct amount of fuel enter? How could you then have correct combustion?

[jlmoulto]

Scud,

Just because she hauls A$$ at 55 when you crank her does not mean she is firing on all cylinders. My 850 pulled like the devil. In fact, I swapped with a good friend who runs a Yamaha FZ1 and his comment was "Man, that thing has some real torque." He's been riding for about 15 years. He was shocked when we discovered the problem.

As for idle, I was not aware of a problem until I felt a cold pipe (that warmed somewhat possibly from some firing and heat from adjacent pipes)

[Scud]

Not sure if this will help, but when I returned from a ride a few days ago (20 miles), I touched the pipe on number 1 and it was sizzling hot like all the others. This tells me that the cyclinder must be firing and getting hot, I cannot see how heat like that could 'leak' over from number 2 cylinder.

I agree Keith, the gold on the rim and a shine on the threads is weird, but as I mentioned in a previous post the plug is starting to show a little carbon on the rim.....weak spark...hmmm.. I did swap coil leads from #4 to #1 with the same results and #4 when it had #1 lead on it ran fine (plug was tan).

I will shoot a photo of it and post it for all to see again. Maybe I should just get some Accel coils and a Dyna ignition and rule out spark. If I only had a money tree...

Scud

[gsBert]

well, if your other 3 cylinders are firing fine, then your coils work.
save the money.
could be the plug cable, but have you disassembled the carbs yet?
i'll bet you have a diff size pilot/main/needle in carb one or your mix screw is turned differently (or the others are missing the o-rings)

[Scud]

Bert, thanks for the info...I am in the middle of painting my house (inside), so I have not had time yet to remove the carbs. More then likely it will be the second week of August unless I can get to it this Saturday for a few hours.

If I can at least pull them off and look at the jets I will let you know what I find. Sorry for being ignorant but is the adjustment for the needle under the rubber boot in the CV carbs?

Thanks again,

Scud

[gsBert]

if you mean the diaphragm by "rubber boot" yeah, the slide holds a needle under the spring, there are notches in the needle, with a clip in the notch to hold the needle at a certain height. make sure allthe clips are at the same notch. press the needle flat on a table to remove the clip, hold your finger on the !@#@! clip so it doesnt go shooting across the room, its near impossible to find on a grey carpet...

theres a small white washer that goes under the clip and a larger orange one that goes above the clip (the spring presses on that one). make sure you install them in this order (bottom to top) on the needle:
small white washer, clip, large orange washer, spring