surging, poor idle, fuel leaking from carb overflow tube

[prosnomonkey]

Did some riding and data collection today, this is what I found:
All the previous riding I have done was with the Fuel Adjusment screws at 2 1/2 turns out
When I turned the screws to 3 turns out, the surging got worse as in it happened more often and the surge was more dramatic
When I turned the screws back in to only 2 turns out, the surging almost went away.
Do I need turn the screws further in to eliminate the surging say to 1 1/2 turns out? Will the engine run too lean? Anybody know what might be going on here?

Secondly, When I got home just out of curiosity, I put the bike on the center stand, and while the engine was running, I pulled the spark-plug caps off. When I pulled the right hand spark plug cap, the bike died almost immediatly. I replaced it, restarted the bike and pulled the left hand spark plug cap, but this time the bike just kept running albeit at a lower idle. (Right/Left as one sits on the bike)

Is this normal? I assume not, as I had read somewhere else here that this is another way to sync the carbs

Thanks again for your time

 

[Gorminrider]

I don't know what's going on- I can only guess.... surging and idle-mix are two different issues, to me, anyways, and I worry when it seems fiddling with one issue fixes the other...

The more the throttle is opened ,the less important the idle-mixture is.

However, it may be a clue that turning the idlemix screws IN is reducing fuel at the manifold....

per idle mix,
here's a place to look:
http://members.dslextreme.com/users/bikecliff/images/highest_rpm_plug_chop.html
here's a pdf:
http://members.dslextreme.com/users/storagecliff1/images/Adjusting_Idle_Mixture_on_CV_Carbs.pdf

as to "...as I had read somewhere else here that this is another way to sync the carbs" yes,it has been suggested as a way to synch two-cylinder bikes,because they are much simpler than the fours but synching is done at the throttle plate opening and not the idle mixture. Idle mixture and valves and plugs etc is done First. Synching is the final act...

 

[Gorminrider]

...I forgot to include this guess...perhaps the vacuum slides are sticking...

AND...it may be that the "surge" is when your bike is finally operating properly. You would feel a surge when the cylinder that wasn't working suddenly does.

 

[prosnomonkey]

I checked the slides when I did the bench sync by moving them up and down with my fingers and they seemed to be operating ok... smooth up and down movement with no hesitation. Is there another test I should do? I am going to go ahead and replace the float needles and the throttle cable to make sure this is not the issue
Jeremy

 

[Gorminrider]

good, good... it took me awhile to realize one of mine was sticking so I had to mention it. again.That new throttle cable is a little money well spent by the sound of it. ...new floatneedles is great but of course they seal to "seats". I've not yet had a problem with these myself, beyond cleaning 'em and checking for corrosion .

and I guess you've been over the wiring to be sure there's no possibility a wire to the coil or ignition is intermittently grounding or open circuiting.

 

[prosnomonkey]

I thought about the wiring issue, and as far as I got was checking the spark plug gap, which is ok. I don't know how to check the wire for grounding issues, and don't really know how to troubleshoot electrical issues. I did notice though that when I grab the wires I get a little tingly shock, more so on the left cylinder.

The fact that it runs on the right cylinder only but not the left seems odd to me. Is this normal, an indicator of what's going on with the surging, or a separate issue?

 

[prosnomonkey]

Took the carbs apart to change the float needle and on a hunch I put the floats in some water to see what they would do (I assume they should float, hence the name) One float sits level, the other doesn't and I can hear liquid in the uneven one. Not sure if this is the source of the issue, but I'm getting at least one new float. Should I replace the second as well?

 

[Gorminrider]

haha!Good find.
It's certainly an issue. You have to fix it. Bike will run better.
Replace both? if they are both corroded, you pretty well must... but personally, given I thought it was a failure of manufacture- a single "weak-point" I would try to fix the bad one and inspect the other closely.

 

[BigD_83]

I thought about the wiring issue, and as far as I got was checking the spark plug gap, which is ok. I don't know how to check the wire for grounding issues, and don't really know how to troubleshoot electrical issues. I did notice though that when I grab the wires I get a little tingly shock, more so on the left cylinder.

The fact that it runs on the right cylinder only but not the left seems odd to me. Is this normal, an indicator of what's going on with the surging, or a separate issue?

It sounds like your plug leads and/or hoods are cracked. This could definitely lead to problems. It's a fairly easy fix, depending on the type of coil you have. Some of the stock coils are epoxied in place, hence the popular upgrade to Dyna coils.