carbs back on. One pipe cold. GS1100G

[Redman]

Had carbs off and apart,

Just for general interest: here is picture from back when first one just out of the dip. Second one ready to go in. 3rd &4th awaiting clean up before disassembly.


Major objective was to replace the orings in the starter/choke mechanisms and the rubber seal on the starter/choke plunger. THis was my last suspect in the "creeping up idle" problem. Had perviously done intake orings, intake boots and airbox boots and sealed airbox ends and halves.
Anyway, without getting into too much detail of why I was doing this, let me just say that it was running smooth last fall.

And while carbs apart did the carb dip (new can of Berryman). Each carb body (and jets) for about 24hours.
And replaced the other orings.
Followed each step in the carb cleaning series (although dont have comporessed air, and dont really know what opening/port is suppose to go to what other opening/port).

Got the carbs back together, Did a bench sync with the "sliver of light" method and check it also with two 1/16th drill bits.

Got carbs back on. Air screws at 3 out. It starts up, but pipe 3 still dead cold when others warm up hot hot in a minute. Will rev, but slowly. And isnt at all smooth. Carb 3 does have gas in bowl (flow out drain if open drain). And pulg 3 is firing, plug did not look wet.
THis is worse than it was.

So, my question at present:
I suppose it does not make any scence to proceed to carb sync, does it?

I suppose pull carbs back off, and see what I find with carb 3.
Cant image what might be wrong. All the jets looked good, could run wire thru them all. Diaphrams good. Float neddles operate well. Float screens clean. Rubber plugs just a couple years old. Float needels great, not at all knotched (I suspect not original).
And yes, I have carb body 1 and 4 in proper place. And, yes, I have the vent tees and the fuel pipes in the right places.

ANyway, the one pipe being cold, that isnt something that a carb sync is gonna take care of is it?

Dave (a sad discouraged annoyed Dave).

PS: last I check compression they were in the low 130s and upper 120s.

[JEEPRUSTY]

I have tired eyes but can maladjusted valve lash be a cause for an unburned fuel charge?

[TheCafeKid]

You need to assure the pickup tube for the idle circuit is cleaned out. Ghats the brass tube sticking out of the carb body when you remove the float bowl. One single strand of copper wire is just about all that will fit. Also the corresponding port in the bowl needs to be clear too.

If those are positively clean, you may need to open the adjustment screw a little more. 2.5-3 turns is a baseline.

[Redman]

You need to assure the pickup tube for the idle circuit is cleaned out. Ghats the brass tube sticking out of the carb body when you remove the float bowl. One single strand of copper wire is just about all that will fit. Also the corresponding port in the bowl needs to be clear too.

If those are positively clean, you may need to open the adjustment screw a little more. 2.5-3 turns is a baseline.

I made the "special tool" as described in the carb cleaning series (wire from wire brush stuck in match stick), but I was wondering if that not long eneough. Maybe I will explore that further, now that you mention it.
If that tube is the starter/choke circuit,, hum, then it must need to go all the wqay up to the top where that starter/choke mechanism stuff is.... hum.
And have been puzzled about that thru hole thru that tube by the barb base. But..anyway.

And maybe try further on adjust screw.

Thanks Josh.

I have tired eyes but can maladjusted valve lash be a cause for an unburned fuel charge?

Valve clearance adjusted last year, so less than 2000 miles ago.
And was running better last fall.

I tired too.
(Work has been frustrating/annoying. And working on bike was suppose to be my recreation.)



And now it is way past my beddy-bye-bye time.
Will check back tommorow for any other words of wisdom.

[Don-lo]

I would try a new spark plug in #3

[1948man]

+1 on the sparkplug. It's a really cheap, fast, non-frustrating way to hopefully get lucky. My bike has dropped cylinders because of fouled plugs and responded to new plugs or cleaning the bad plug. I realize you have already thought of the plug and checked it but it might start so you can sync which might also discover that #3 is way off.

[rustybronco]

What is the secondary resistance of the coils; plug cap to plug cap?

[ChicagoBob]

Choke plunger problem?

I had this problem with the VM22S carbs on my 1978 550. I suspected a petcock leak, but it turned out to be a loose choke plunger, which richened the circuit in the #3 cylinder (and was, of course, not findable until I had the carbs off and separated).

[spyug]

Same problem on my Kat project last year. Carbs had been cleaned and the engine ran fine and strong when first started but it sat for about 5 months and while it would start, #2 was stone cold. Pulled and recleaned all carbs. Bike ran fine again with everything heating up.

Try the plug change first but my moneys on the dirty carb.

Good luck.
Spyug

[850 Combat]

Just for grins, switch the 1 and 4 plug leads as well. My money (if I had any) would still be on the carb as well.

[ddaniels]

Had the same problem on mine....twice. Both times, the ports in the bowl, where the choke pickup tube goes down into, was clogged. I used a bread twistie with the paper scraped off as my tool. Worked great. After running that through the ports, spray carb cleaner in one end and it should shoot out in a nice stream at the other end. If it sputters, it's still clogged.

[Redman]

I would try a new spark plug in #3

What is the secondary resistance of the coils; plug cap to plug cap?

Am not at all suspecting ignition problem. CAn see good spark on the plugs.

But did look into it.

24.9 K ohms cap 3 to cap 2.
Factory manaul says is suppose to be 30 to 40 k ohms.
So I checked each cap, each one is just a bit over 5k, which I understand is what they are suppose to be (and when they go bad they go real high or open).
And I checked cap 1 to cap 4 and its about the same. So I do not suspect any problem there, at least no related to pipe 3 staying cold.

More importantantly:
And I swapped plug 2 & 3, and pipe 3 is still cold.

And I tried opeing the adjust screws to 4 and 5 and still pipe 3 cold.

Had the same problem on mine....twice. Both times, the ports in the bowl, where the choke pickup tube goes down into, was clogged. I used a bread twistie with the paper scraped off as my tool. Worked great. After running that through the ports, spray carb cleaner in one end and it should shoot out in a nice stream at the other end. If it sputters, it's still clogged.

So I quess I am pulling carbs back off.

And now, tonight, I got gass dripping out the airbox drain.
(I know, check the oil.)




It was running fairly well last fall, except fpr the "creeping idle problem".
I pull off carbs, mostly to replace the oring and the rubber cap on the starter/choke mechanisms. And do the carb dip/cleaning and replace the other orings.
And now things are worse.
Maybe I dont deserve to have a nice classic bike (dare I say "vintage").



Dave



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[Redman]

Ah Ha !

Float Height adjustment.

#2 and #3 looked like with float all the way up the needle may not have been closed.

And my thanks to Dale RustyBronco, was good to discuss this with Dale.

I reset the float heigth at 22.5 to 23.
Carbs back on, and no drippy drippy gas.
And starts up and runs well, and all four pipes heating up about the same.

Dont know how a carb cleaning/dip would require the float height to be readjusted ....
Some therory:

- Maybe I didnt get the floats back into the appropoiate carb body. Maybe I didnt get float needles back into appropiate carb bodys. But I dont think so.

- Maybe the carb clean/dip effected the little spring in the needles.

- Maybe the float seats were not previously inserted al the way, and now they are.

- A couple years ago I adjusted the float heighth to to shorter end of the range (21.5mm) for higher fuel level. Did this back when engine was running hot hot (per recommendation that this would richen things a bit.). And now, that something else changed, that was too close to the float needle not closing.


A couple things I found:
- WHen gas dripping out of the air box, can take off the air box, and before removing carbs, turn gas back on (auxillary tank) and then see which carb is dripping gas.
- Then when reinstalling carbs, before putting back airbox, can turn on gas to check for gas overflow. And can start bike. (I had thought I have seen many statments that will not run without airbox. BUt my 1100G did run, maybe not rev up very much, but did run,) So I could check out that gas not dripping and bike would run and could check that all pipes heating up.


Anyway, ......
Now onto the air screw adjustment and the vacuum ballance.

Thanks again Dale.

Dave.

[chuck hahn]

Bread tie is my choice of tool in the pick up tube as well,, it gets all the way to the bottom. I dont know if the cans of compressed air at computer and electronic stores will do squat or not. I run my compressor at 90 PSI when i blow out carbs.

[Redman]

First attempt was frustrating.

Took 3 occassions over 4 days to develope a "light touch" with the adjust screw/wrench tool.

Third attempt was much better.

Maybe 45 degrees in a couple days for a test ride.

Thanks Cliff.

Thanks again Dale.

Dave


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