Cylinders 2 and 4 are dead cold!

[RiceCooker]

this might be related to this post:

http://www.thegsresources.com/_forum/showthread.php?p=2076079#post2076079

My problem might escalate all the way to valve adjustment...(Exhaust valves maybe, I tried to be brief but just couldn't but Please Advise ! )

My story:

I got this 1983 GS 1100 GL has 8500 mi. (that's right less than 9k miles)
I cleaned the carbs, shinny freed jets, no leaks, floats leveled, new gaskets etc... all-in I'd say.
I tested the coils ( 3.2 and 3.4 Ohms)
this is not my first bike but I'm not an expert either... this looks like a bucket of gremlins I've been catching but I'm stucked with this one....

Bike starts right up, but running only on cylinders #1 and #3 ( 2 and 4 are dead cold )
I recall riding the bike with the old spark plugs and after a few laps around the block, all exhaust pipes were hot.

this happens no matter how I set the carbs ( 2 1/2 turns out, now 1 1/2 )
or even if I switch the coil cables.... 1to4 or 4to1, 2to3 or 3to2.
I just put new recommended NGK B8ES spark plugs, they all have spark, even the old ones had visible spark.

I'm very positive I can rule out carburation, All my floats have gas, all cv intake sucks enough to get my hand stucked on it and pull gas if I do so, all sliders are free and happy bouncing. Even if I had synched the carbs at high revs I'm guessing it wouldn't make any difference since I tried different configurations for the pilot air mixture screw. am I right? I know it's running lean now ( 1 1/2 turns out)

I'm also on the positive side I can rule out ignition timing since I got spark and no matter how I set the coils I cannot transfer the problem to the other cylinders. The symptom appears to be the same, I would say If only one coil was firing I would have cylinder 1 and 4 hot or cold ... in the same way 2 and 3 would be hot or cold but not mixed as I have it now... could I say is firing on time? Also, the bike will stumble and die if I remove any of the coil plugs from the spark plugs.

My conclusion and my fear is exhaust valves 2 and 4 are leaking? and somehow they work at high revs? as a low miles bike, I think they never serviced the valves, it's all stock all unmolested.
would anyone have another conclusion? thanks!

 

[Nessism]

Most likely the carbs. You might want to go though the carb rebuild tutorial linked in my signature to see if you missed any steps, and also check the Newbie Mistakes thread also linked, just in case anything applies.

Good luck

 

[RGM]

It is always one of three things, Ignition , compression or fuel/air. What is your compression at?

 

[posplayr]

this might be related to this post:

http://www.thegsresources.com/_forum/showthread.php?p=2076079#post2076079

My problem might escalate all the way to valve adjustment...(Exhaust valves maybe, I tried to be brief but just couldn't but Please Advise ! )

My story:

I got this 1983 GS 1100 GL has 8500 mi. (that's right less than 9k miles)
I cleaned the carbs, shinny freed jets, no leaks, floats leveled, new gaskets etc... all-in I'd say.
I tested the coils ( 3.2 and 3.4 Ohms)
this is not my first bike but I'm not an expert either... this looks like a bucket of gremlins I've been catching but I'm stucked with this one....

Bike starts right up, but running only on cylinders #1 and #3 ( 2 and 4 are dead cold )
I recall riding the bike with the old spark plugs and after a few laps around the block, all exhaust pipes were hot.

this happens no matter how I set the carbs ( 2 1/2 turns out, now 1 1/2 )
or even if I switch the coil cables.... 1to4 or 4to1, 2to3 or 3to2.
I just put new recommended NGK B8ES spark plugs, they all have spark, even the old ones had visible spark.

I'm very positive I can rule out carburation, All my floats have gas, all cv intake sucks enough to get my hand stucked on it and pull gas if I do so, all sliders are free and happy bouncing. Even if I had synched the carbs at high revs I'm guessing it wouldn't make any difference since I tried different configurations for the pilot air mixture screw. am I right? I know it's running lean now ( 1 1/2 turns out)

I'm also on the positive side I can rule out ignition timing since I got spark and no matter how I set the coils I cannot transfer the problem to the other cylinders. The symptom appears to be the same, I would say If only one coil was firing I would have cylinder 1 and 4 hot or cold ... in the same way 2 and 3 would be hot or cold but not mixed as I have it now... could I say is firing on time? Also, the bike will stumble and die if I remove any of the coil plugs from the spark plugs.

My conclusion and my fear is exhaust valves 2 and 4 are leaking? and somehow they work at high revs? as a low miles bike, I think they never serviced the valves, it's all stock all unmolested.
would anyone have another conclusion? thanks!

So do a compression test?

 

[BigD_83]

Can you confirm...

have you adjusted the valves?

 

[RiceCooker]

I haven't adjusted the valves also I don't have a number of PSI on each cylinder. I'm guessing, simply my thumb being blown away from the spark plug hole could not be accurate enough this time
I've never had this kind of problem in other bikes so I'll borrow a tool, let you guys know.

thanks again everyone.

 

[posplayr]

I haven't adjusted the valves also I don't have a number of PSI on each cylinder. I'm guessing, simply my thumb being blown away from the spark plug hole could not be accurate enough this time
I've never had this kind of problem in other bikes so I'll borrow a tool, let you guys know.

thanks again everyone.

If it is blowing your finger away, it is likely enough pressure to fire.

 

[Guest]

valve adjust is not an escalation, it is the baseline.

 

[Brendan W]

Is it possible you have the HT leads connected the wrong way? Isn't this model an odds and evens i.e. 1/3 & 2/4 instead of 1/4 & 2/3 ?

 

[Guest]

Is it possible you have the HT leads connected the wrong way? Isn't this model an odds and evens i.e. 1/3 & 2/4 instead of 1/4 & 2/3 ?

NO it is not they fire , 1-4, and 2-3,

 

[barnbiketom]

I'm very positive I can rule out carburation, All my floats have gas, all cv intake sucks enough to get my hand stucked on it and pull gas if I do so, all sliders are free and happy bouncing. Even if I had synched the carbs at high revs I'm guessing it wouldn't make any difference since I tried different configurations for the pilot air mixture screw. am I right? I know it's running lean now ( 1 1/2 turns out)

What makes you think all the INTERNAL passageways aren't clogged??? pilot jet? air bleeds? etc etc?? I bet carbs are at fault....
It will probably only take FIVE SECONDS to confirm.
Spray a small shot of ether or even wd-40 into the airbox or sync ports when bike is idling. if 2 and 4 pick up.. you have plugged carbs. easy

 

[Guest]

RiceCooker, you are all over the place chasing your tail. Adjust your valves, do a compression test, rebuild your carburetors properly (If you haven't torn them down completely and soaked them for 24hrs. in carburetor dip, you have been wasting your time even touching them) Nessism gave you the best advice in the beginning and you ignored it. The answers are there in those steps.

 

[RiceCooker]

Ok, tonite I'll do this...
- check compression (with a proper tool )
- spray carb cleaner on 2 and 4 and see if idle speeds up

What makes you think all the INTERNAL passageways aren't clogged??? pilot jet? air bleeds? etc etc?? I bet carbs are at fault....

You are right, I soaked them, sprayed them with carb cleaner and blew air through the passages... that doesnt mean they didn't get clogged again by other means

valve adjust is not an escalation, it is the baseline.

I agree that is the baseline but I meat escalation from simple/cheap/fast to complicated/expensive/time consuming. If I can avoid a valve job by cleaning the carbs that's a good day
there's always the risk of screwing the gasket up and had to get a new one.

 

[BigD_83]

You seem to be under the impression that checking and adjusting your valves is an expensive, time-sucking job. Nothing could be further from the truth.

Just get'er done, as they say. Even if a complete strip and dip cleans up the carbs for you, the valves still need to be checked and adjusted. The good news is, that can be done while you have the carbs apart.

 

[Guest]

there is no avoiding valve adjustment. and it is much easier than a proper carb cleaning. but hey, maybe i am wrong here.

 

[RiceCooker]

RiceCooker, you are all over the place chasing your tail. Adjust your valves, do a compression test, rebuild your carburetors properly (If you haven't torn them down completely and soaked them for 24hrs. in carburetor dip, you have been wasting your time even touching them) Nessism gave you the best advice in the beginning and you ignored it. The answers are there in those steps.

Hi OldVet I'm guessing they got clogged as barnbiketom implied.
I didn't want to ignore Nessism, but I tried to simplify my carburation section. maybe this makes more sense why I ruled carburation out...

Carburation...
I cleaned n flush the tank, screen is good as new. I rebuilt the petcock vacum valve, orings etc. I took the carbs out of the rack and disassembled apart. Soaked the jets overnite basically all the brass-ware, sprayed them the other day meanwhile I soak the carbs assembly. I freed the lil holes, spread coming out of jets was even. the rule was if I see a passage blew it in with cleaner until I see a good spread , then again with compressed air.
Main jet needles are shinny, same high and same shape. sliders go up and down at the same rate.
Intake passage to the floats have new orings and needles seal properly and their springs all look the same to me. stop all at the same volume on the reservoir. floats float no leaks, free to bounce on the intake needles happily.
Choke plungers seal or don't seal as they supposed to, put new orings on vacuum connectors and gas intake connectors, slider main needles are at the same high, springs look good and diaphragm rubber looks good and seal. they all go up and down at the same rate.
I assembled them back on the rails, bench synched them and visibly test the idle spray with compressed air. they dont leak gas unless I force gas into them. The way I checked for vacuum leaks is blowing with my mouth through the lines in the connectors.

although... again it doesn't mean they got dirty again by any means or acts of god.

I think the rule should be check everything every time you work on something and hopefully I'll get this rice cooker to run top notch.
If they are clogged, i'll take a look at Nessism links, maybe I missed something.

 

[Guest]

RiceCooker, you are missing the point entirely, there are no shortcuts that work. I can tell you that everyone I know who have tried to work on these carburetors including an excellent Harley mechanic that thought spray carburetor cleaner would work were quite shocked at the crud boiling out of their pristine looking carburetors when put in carburetor dip. You are still in the kicking and screaming stage but eventually you WILL drag yourself to the realization that only the right way works on these old Japanese carburetors if you ever do it the right way. I was dragged there myself so I know what I say is true. STOP WASTING YOUR (and our) TIME and listen for a change. Just a little advice from an old fart who has been there and done that. PS petcock rebuilds are known to fail unless you are extremely lucky.

 

[RiceCooker]

there is no avoiding valve adjustment. and it is much easier than a proper carb cleaning. but hey, maybe i am wrong here.

You seem to be under the impression that checking and adjusting your valves is an expensive, time-sucking job. Nothing could be further from the truth.

Just get'er done, as they say. Even if a complete strip and dip cleans up the carbs for you, the valves still need to be checked and adjusted. The good news is, that can be done while you have the carbs apart.

Well overall the adjustment would take longer If i need to order shims and new gasket. I believe this GL needs shims instead of rocker adjustment right?
I promise if compression test tells me I need to adjust the valves, i'll soak the carbs again till I get the parts for adjustment... Just wanted to avoid to buy shims and maybe a new gasket...

 

[RiceCooker]

RiceCooker, you are missing the point entirely, there are no shortcuts that work. I can tell you that everyone I know who have tried to work on these carburetors including an excellent Harley mechanic that thought spray carburetor cleaner would work were quite shocked at the crud boiling out of their pristine looking carburetors when put in carburetor dip. You are still in the kicking and screaming stage but eventually you WILL drag yourself to the realization that only the right way works on these old Japanese carburetors if you ever do it the right way. I was dragged there myself so I know what I say is true. STOP WASTING YOUR (and our) TIME and listen for a change. Just a little advice from an old fart who has been there and done that. PS petcock rebuilds are known to fail unless you are extremely lucky.

I hear you OldVet, I might sound like a prick but I just type too much maybe?...
I'll be glad to adjust the valves and will soak the carbs again, maybe run a waterpump on the intake overnite.... we will see.
This is a learning process and hopefully this will help somebody else in the future for this particular bike.
I enjoy WASTING my time on bikes and wanted to share this experience on this forum.
You can always subscribe off or stop posting if this is a waste of time to you in my opinion .
I got Lucky on the Petcock because it works quite well by the way, doesn't leak, carbs suck on the vacuum and appears to let gas flow on reserve and on, primary always work.

 

[BigD_83]

Well overall the adjustment would take longer If i need to order shims and new gasket. I believe this GL needs shims instead of rocker adjustment right?
I promise if compression test tells me I need to adjust the valves, i'll soak the carbs again till I get the parts for adjustment... Just wanted to avoid to buy shims and maybe a new gasket...

In what did you soak your carbs?

Yes, you will need shims unless someone has swapped out the engine for a 16V design.

Member Steve, has a little spreadsheet to help you with that.

http://www.thegsresources.com/_forum/member.php?u=484

The Shim club (Member Ghostgs1) can also help you with buying/exchanging shims.

http://www.thegsresources.com/_forum/showthread.php?t=122394

Regardless of the compression numbers, valves need to be checked, and the shims inventoried. At any rate, the bike has a much better chance of running properly if the valves are adjusted properly.

TKent has a trick for checking your clearances. Don't quote me on this but it goes something like this:

if you cannot fit your thinnest feeler gauge, and the shim still turns under the cam lobe at TDC, then you have "some" clearance. Go down one size in thickness. If you cannot spin it at all, then go down two sizes.

It takes about 15-30 minutes to do the valve check...Be prepared with a new valve cover gasket though. Even if you don't have one on hand, you can afford to wait if it's not firing on the #2/4 pots. You shouldn't be riding it at this point anyhow.

Once you have all of your shims inventoried, then you can contact Ray (Ghostgs1) for the shims you need.

By the way, I don't know why, but I sense you might be a long ways away from the US. Why don't you let us know where you call home? Somebody might be handy to you.

Find your User CP at the top of the page, create a signature with your bike, and fill in your location information.