Exhaust temps not even?!?!?!?!

[flyanimator]

Hi everyone, I've searched throught the forum for something similar to my problem and found a very recent post from a member who is experiencing the similar symptoms.

http://www.thegsresources.com/_forum/showthread.php?t=160566

So the problem is that my exhaust pipes on one side(cyl 3 & 4) are getting significantly hotter that the other side(cyl 1 & 2). I have not measured them with a thermometer as i do not have one but have used a simple spray test. I spray a small amount of liquid (i used pb blaster as i had it on hand) on each exhaust pipe and see what it does. On Cyl 3&4 the pb vaporizes immediately as it hits the pipe and on cyl 1&2 it does not evaporate at all. What could be causing this difference in exhast temps?

Everything is stock on the bike (1980 GS1100L w/bs34ss carbs) except for the ignition which is now a dyna s with accel coils and wires as well as the coil relay mod. Valve adjustments were just completed, Carbs dipped and rebuilt with new gaskets, needle valves and o rings, float set at correct height, jets are all stock sizes. I just balanced the carbs with a carbtune pro. Exhaust is stock 4-2 pipes. Air box has been sealed, has new air filter, new airbox to carb boots as well as carb to head boots. idle screws (not sure if that's what their called) are set to 2.5 turns out from lightly seated as a starting point. Spark plugs are a few months old but have not seen any mileage on then as the bike was being worked on at the time. They went in clean and came out as seen in the pictures on the link after running the engine a few times while I was synching the carbs. The plugs are cyl 1-4 from left to right.

http://www.facebook.com/album.php?aid=2069195&id=1221334145&l=ab5d42cfb4


Any help or insight is greatly appreciated. Thank you!!!

 

[Dave8338]

It looks like a lack of fuel to the #1 and #2 holes, to me. You can see that #3 looks good and #4 may be a tad rich, but leave it alone for now.

How does the bike start on choke? What happens when you drop the choke? With the air box cover off and filter out, spray a little two stroke mix into the air box. Does the idle speed increase? It should, judging from your plugs.

I think that you're still lean on the first two carbs and my gut is telling me that it is likely a blockage, somewhere. Did you pull the choke plungers when doing the carbs? New orings, there?

 

[flyanimator]

It starts fine on choke, almost immediately. I don't remember what it's like when i take the choke off but i'll check on that and get back to you.

The carbs were completely disassembled and dipped for 24 hrs in berrymans carb dip. then all passages weregone through with carb cleaner to make sure everything came out. All of the o-rings were replaced including the choke plunger.

I know carbs 1 & 2 are getting getting fuel to the bowls, but i'll try the 2 stroke mix idea and see what happens.

 

[flyanimator]

I think I may have found something, but I'm not really sure what it means. I just went out and started the bike and it started right away with a little choke on it. I did a simple check to see if plugs 1 and 2 were firing by pulling the cable off and the rpms did not change. I did each of these individually and then together, still no rpm change. I noticed, however, that when i put the plugs wires back on halfway (not snapped on to the plug end but just kind of resting on it), my rpms increased!!!! Does this signify bad plugs on 1 and 2, or bad plug wires??? I did the same temp check as before with the pb blaster and it now evaprates as soon as it hits the pipe on all four cylinders (with the plug cable halfway on as described previously). One thing is that now with the cables this way i'm getting some smoke out of the 1&2 exhaust (smoke looks white, too rich maybe???). Any thoughts are greatly appreciated, Thank you All for your help.

 

[tkent02]

I think I may have found something, but I'm not really sure what it means. I just went out and started the bike and it started right away with a little choke on it. I did a simple check to see if plugs 1 and 2 were firing by pulling the cable off and the rpms did not change. I did each of these individually and then together, still no rpm change. I noticed, however, that when i put the plugs wires back on halfway (not snapped on to the plug end but just kind of resting on it), my rpms increased!!!! Does this signify bad plugs on 1 and 2, or bad plug wires??? I did the same temp check as before with the pb blaster and it now evaprates as soon as it hits the pipe on all four cylinders (with the plug cable halfway on as described previously). One thing is that now with the cables this way i'm getting some smoke out of the 1&2 exhaust (smoke looks white, too rich maybe???). Any thoughts are greatly appreciated, Thank you All for your help.

I would say bad wire caps are the problem, the smoke is from unburnt fuel accumulating in the pipes.
Pull the plug caps off and clip off the last 1/2 inch of wire, reconnect them and go ride for a while. You may need to replace the caps, or perhaps the caps are not the right type?

Are the little metal plug connectors screwed on the end of the plugs or not?

Is there any difference between these and the two caps that work properly?

 

[flyanimator]

That is the prognosis that my father and i came up with as well.
Yes there are little screw on ends on the plugs (they look like small metal nipples) and all four plugs have the same. I know they originaly don't come with these but the plug cable ends from the accel coils are made for this tipe of thing. I will be measuring the resistance of all four cables and checking out the wire caps for corrosion or a bad connecion as well and report the findings. Thanks to everyone for your help and suggestions.

 

[flyanimator]

ok, so I tested the spark plug cables and they are all good. So i went on to pull the spark plugs and fount that the ones on cyl 1&2 did not spark when i cranked the engine and laid them on the case. So i'm thinking that the plugs on cyl 1&2 are bad. I just ent down to the parts store and bought another set of plugs (ngk d8ea) and will replace the suspect ones tomorrow and see what i turn up. do any of these symptoms lead anyone to believe there may be a problem elswhere? please give me your opinions so I can be thorough in my tests tomorrow. Thank you all again for your help.

Best regards,
-Rudy

 

[Daddio87]

me 2

me 2

I am experiencing the same issue..my pipes on the left side are not getting hot and the ones on the right are..i had my bike apart and it didnt do this before and now it is....do u think its a fuel lost...i do have spark when i checked and the bike does start up and run but didnt when i let the choke out...are we having the same problem???i really need to ride so i need to get to the bottom of this issue

 

[BassCliff]

Hi,

New spark plugs and plug caps are a cheap and easy fix. Replacing them will eliminate this part (spark) from your troubleshooting process. You know both coils are generating spark because #3 (right) and #4 (left) are sparking. The other parts of the equation are fuel (clean carbs, etc) and compression (valve adjustment, etc).

There are electrical/ignition troubleshooting tips on my website along with valve adjustment guides. Help yourself and keep us informed. Mr. Daddio87, you may want to start your own thread so there will be no confusion as to what advice is going to which poster.


Thank you for your indulgence,

BassCliff

 

[Dave8338]

Any news yet, Rudy? :-k

 

[flyanimator]

Sorry for the suspense, Dave. It turns out I had 2 bad plugs. Bought new ones last night and replaced the ones that were not working a little earlier and voila!!!! tested them by pulling the plug cable off and sure enough, rpms dipped. I'll test the exhaust temps tomorrow morning. Baterry is a little low from testing yesterday so I hooked it up to the charger. Thanks to everyone for your suggestions.

Has anyone ever gotten a bad spark plug? These were basically new, just been sitting in the bike with no action for a few months, no miles on them, and it turns out that two of them were bad. What gives? Is ngk dipping on quality or was this just an astronomical stroke of bad luck?