1980 GS850GL Need some advice

[Uncamitzi]

That's what I thought.... This is a fuel problem (so far) and I've just about got the idle mixture dialed in. I can only spend an hour or so at a time doing tweaking this and it's taking a long time. The information on the carb tuning link from the sticky in this section is a help. It does seem counter intuitive that you do the main jet first...and then work your way down to the idle... it calls for a lot of carb off and on for those of us who are just getting our feet wet on Zen and the art of motorcycle mechanics. But... I'm trying to bow to the wisdom of the masters here...I can't see that anyone has steered me down the wrong path yet. Well..back at it.. I managed to foul up (with carbona) #1 with my tweaking yesterday.
SO this can remain in the carb/Fuel/ Exhaust section ...our brief interlude with the coils is at an end (at least here) Thanks for the help... I'll be back

[Uncamitzi]

I think tomorrow I'm going to take the carbs back off and go back to the #115's that are stock. I can't seem to get anywhere with the idle mixture....and I'm starting to get frustrated

[Uncamitzi]

Looking for answers. I keep seeing Steve telling people how to start their motors using the choke. In the 3 years that I've had this bike only on cold damp mornings have I ever had to used the choke to start my bike, which leads me to believe I may have problems not addressed. The PO obviously did some work on the carbs. He gave me the remains of the Dyno Jet kit that he used to "fix" the carbs. In this kit I have the stock #115 mains that he took out and replaced with the #165's I rejetted with the 145's that were in the kit.. but didn't do anything to the air jet ... There were only 3 in the kit that he gave me 40's I think..the kit is in the garage right now and I'm just doing this from memory, and I can't remember the size of the air jet that was in there, but... the fact that I've hardly ever had to used the choke to start the bike makes me wonder why. Even, now after the rebuild, if I pull the choke it merely kills the engine. My thought.. The needles are set to the wrong height. ... too rich? I'm also going to revisit the float valves and float height... My test ride today was rough and ... my charging system has let me down again...

I'm not having a great week.

[Uncamitzi]

Pulling the carbs today again. After I got the charging system working again (broken connector from the stator, dirty fuse box connections and some other shortcuts re-repaired) I took a 30 mile ride with mixed driving some freeway and some city. When i got back I pulled the plugs and found that #3 and #4 were fouled again. The idle mixture screws are just a hair off (1/2 turn) from being seated... on carbs.. #3 and #4. #1 and #2 are tan and seem to be burning fine at about 2 turns. Going to check the float valves and heights again. I've made the fuel height gauge and have mounted a vice on my workbench... I still think that the needle valves and the main jets might be part of the problem too. I'm open for advice still.
I purchased some used coils from Ebay... The primary coils are both at 4.4ohms but I don't get a reading on the secondary, just like the originals that are still on the bike. I'll swap them too while I'm checking the carbs. I still don't understand why the #1 and #2 would be fine with a weak spark split between coils.. on #3 and #4. When I visually check the spark they are all blue white and regular. The reason I mention this is because it still SOUNDS like it might be electrical.
So to recap I've replaced all the orings cleaned and dipped the bodies and parts cleaned all the jet holes and measured the float heights (all were withing spec and I didn't adjust) Right now #1 air mixture screw is at 2 turns #2 is at 2 turns, #3 is at 1/4 turn #4 is at 1/4 turn. I've moved them at about 1/4 turn increments at a time while checking plugs and how the engine runs. I can't lean #3 or #4 any further with the airscrew. (all air screw orings are new)

I'm also concerned about why my choke doesn't seem to work the way that the experienced hands here say it should. Only on cold morning have I used choke to start (which it has always done with a crank and a slight turn of the throttle) other times it just roars to a start (above 55F)

So... I'll be in the garage checking stuff.... I'd LOVE some input.

[60ratrod]

my kz's coils also produced nice blue spark on all 4, but when running, it ran like crap. i swapped the dyna green 3 ohm coils that i had on the gs back on to the kz and she runs like a champ now. i don't know how well those used coils will work out for you. i would recommend getting a set of dyna 3 ohm coils and their wires and see how much different it runs if the used coils don't work

[Uncamitzi]

Reviving a dead thread is like reviving an idle motorcycle... I feel good about doing both. Got the carbs rebuilt, re jetted with factory spec jets, air valves, new rubber plugs, new gaskets... Followed all advice about cleaning the carbs and how to... set the floats, ...got the carbs on (not that easy) got the airbox cleaned, KN filter oiled... Hung and tight.... Fired it up and sync'd the carbs .... was just going to ride it over to the state inspection station to get the paper work done... it rode so well and smooth that after I got it properly licenced I went for a little ride... 100 miles later... I'm getting 42 mpg and the bike just feels GREAT... Thanks for the help.... and I'm really glad this site is the way it is...

Also... re checked the valve shims... they are correct now too. Now some cosmetic touches and some riding.....

[eil]

Nice! Very fun bike once it's all sorted. Love mine to bits.

[Dogma]

Well done. 42 mpg is right where it should be.