Problem is still not solved (1982 GS1100G motor runs rough)

[Anonymous]

Well, the problem has still not gone away totally. Runs great when the engine is cold. Starts to misbehave (runs rough) after a short while. Could be because the engine is warming up or perhaps just something to do with the length of time it is running. I mention the latter because, a restriction in the fuel line could be preventing the proper float levels. I think it has something more to do with a warm engine though? For this reason I suspect the carbs. Any thoughts????

To date,

we have replaced the plugs,

swapped back and forth between a spare set of coils,

grounded the ignitor box, cleaned out the carbs,

turned the air screws down a half turn (the screws were turned out 3 1/2 turns; seems like an awful lot),

checked wiring that could be causing and intermitent problem including kill switch,

replaced the plugs, resealed the air element (which was loose - missing a gasket),

replace the spark plug lead caps,

adjusted float levels.

tightened exhaust headers (there was one small leak)

It is running a bit better, but still spits and farts and runs rough at times. Seems to be worse when the engine warms up. Oh yeah, no.4 sparkplug is sooty, but the rest look fine. I've seen stronger spark, but when comparing to my brothers GS850, they were comparable.

As an aside, when it is running right, the clutch can't hold it. I was thinking about putting a spare Barnett clutch I have, but am reluctant as the springs are bit too strong, my left hand gets cramped after awhile.

 

[Anonymous]

Running Rough

Running Rough

Sounds like #4 is running rich. You did synch the carbs, right? Does it straighten out above idle or hit and miss across the rev line? I just had to pull #3 bowl off my GS850 to cure a fuel problem. Had a pilot jet plugged in the end hole. It would run when cold but you could hold your hand on that cyl. and hear it spit, pop, and fart. Once you got off the pilot system it would run like normal. If it's just idle, there's your problem. If it does it higher in the range, you still have crap in other places. Good Luck, Bob

 

[cbxchris]

You did make sure you had no leaks at the carb boots?

 

[Bill + Karen]

You did make sure you had no leaks at the carb boots?

I second this, look for cracks and check the o-rings that seal them to the head. Bill

 

[Anonymous]

The motor acts up at more than just an idle. It runs rough at idle, roughest at mid-range and clears up a bit but not completely at wide open throttle. Not as bad as running on just two cylinders. It is about as bad as one might expect with one rough running cylinder. Fuel consumption is down from about 270 km/tank to about 200km/tank.

I have not yet tried to re-synch the carbs. Have Manomomonometer coming in on Wednesday. Between the bunch of us that have these GSs, I figure it might be worth the investment. On my Buffalo, I could synch the carbs an odd man out procedure. Haven't quite figured out how to apply that procedure to 4 carbs. Anyone know the rules for this.

No leaks or cracks are visible on the carb boots. I will check these a little bit better.

I am wondering how finicky this engine is on to much air to the carbs. Would a dry stock air element not provide enough restriction for the carbs?

I will revisit all your suggestions.

 

[Anonymous]

if you have done the obvious including valve clearance must be fuel check the needle is polished had one sat for long time get buildup of white
gunk on needle this will stop fuel vapour traveling up needle to carb affects up to3/4 throtle probably idles ok cold because you are running
on choke this is just a thought
ozman

 

[Anonymous]

I have a solution. Sell your GS1100G to Al (see Gen Discussion thread) so he can build one out of two.

Smarass Nick

 

[Anonymous]

Running rough

Running rough

I am wondering how finicky this engine is on to much air to the carbs. Would a dry stock air element not provide enough restriction for the carbs?

Unless the filter is full of holes or just plain gone, I think it's about the most restriction you will get. All of the oil type filters flow more air.