82 GS1100GK making me crazy

[Guest]

I think I just need time to vent.

Background

I've owned this GS roughly ten years now. It ran well enough back in the day but I was younger and had big ideas and such. I had installed a Vance-Hines
V12001-G exhaust, UNI pod filters, and modified the original BS34s with a dynojet jet kit. The exhaust dragged excessively (maybe different peg mounts on the GK?), the filters liked to collect rain, and I was never fully satisfied with the carburetion in that trim.

Of the two racks of carbs I possessed at the time (Have a boxed GS1100GL for spare parts), one had drilled slides for the jet kit and the other had holey diaphragms. I purchased a spare rack of carburetors off of ebay hoping for decent diaphragms and the new rack seemed nice enough that I chose to make that rack my primary set.

Didn't touch bike for a few years and have finally started to return it mostly stock.

I am very familiar with carburetion, I pretty much clean carbs all day 5 days a week. That said I typically only deal with units manufactured within the past 15 years and am not afraid to admit that I'm a generalist and will never know the specifics of a particular unit as well as folks who spend all of their time learning the eccentricities of their favorite machine. Ya'll got me beat.

Let's see. Ok, the bike refuses to rev once it's in the midrange (A little higher in the range than I'm used to seeing on idle/bypass clogs). On the occasional times it gets beyond mid to mid/high it will actually rev out well enough. At idle seems to drop cylinder #2 50% of the time.

Compression at 150 to 145 dry all the way across.
Valves adjusted years ago, but only roughly two hours ride time ago.
New YTX14AHLBS. 6 gauge marine wire positive, negative, and starter wire.
~10 gauge wire feeding fuse panel from solenoid.
OE Suzuki Stator and Reg/rec, shows 13.5VDC on battery running. (gonna go with a 775 once I get the thing back on the road)
Coil relay mod (acts up with or without relay wiring hooked up)
NGK 5K ohm plug caps, all test good. Suzuki coils (Have four to choose from, all test good and no matter the swap I get the same results.)
Stock ignition and wiring otherwise. Have tried two different ignitors with same result. Seems to have healthy spark.

Split carb rack (this is the new rack to me so it's never ran on these ones correctly). Replaced O-rings, thanks to Mr Barr (I think that's his name). Carb bodies thoroughly cleaned twice now. Flow between Idle air jet and pilot jet tube. Flow from pilot to screw, bypass and idle outlet. Flow from main air to main. Float height set. New needles and seats labeled "2.0" (I believe I used K&L units). 40 pilots, 115 mains, 170 main air (tried 160s too), "X3" needle jets, "5D58" needle (could be a zero, tiny numbers). Diaphragms intact with stock springs. OE enrichener plungers, appear good. Rubber plugs installed over pilots. Washer is installed on mains. Needle assembled - washer - clip - poly spacer - poly cap - snap ring. Pilot screws - o-ring - washer - spring - screw head, 2 turns out. Sync adjusters untouched, butterflies resting with first half of first bypass hole exposed on all four (I'm used to seeing more idle issues with sync not high speed stuff but don't figure I can sync an engine dropping a cylinder anyway lol).

New manifolds (Suzuki), new manifold O-rings, OE air box disassembled and cleaned, OE "stacks"/carb boots, new K&N air cleaner on OE cage with screen removed (I hate screens), cage sealed with foam tape type junk.

OE exhaust, mostly rusted out internally.

Running off of auxiliary bottle.

After everything the only thing that made me raise my eyebrow was loose fitting needle jets/emulsion tubes on 1 an 2 versus the other two. I've got another rack of carbs for it I was gonna go ahead and clean to have spares anyway so I figure I may just swap them on next (only the slides from this set will be transferred over).

Well, back to it.

Thanks for listening. This old bike gets in my head sometimes. I figure ya'll might just be the only folks out there that would empathize with my pain right now lol. Any ideas are appreciated.

Thanks again,
JZ.

[RedBaron]

Well, I've gotten my "I know these carbs worked" carbs together now. Had to take the little DJ air correction jets out of the main air circuit and reuse the slides from the suspicious carbs. I listed the pilot air jet as a main air earlier it seems. These carbs ran decent when I parked the bike years back. Seems I was lucky enough to have remembered to drain the fuel bowls. I've gotten all the DJ jets out of them, new O-rings everywhere, and checked the passageways. They're better than they were on removal and returned to OE jetting. The needle jet/emulsion tubes were more snug in these ones. Should give me a better idea what I'm looking at tomorrow evening upon installation. The most frustrating bikes I run into are my own

[tom203]

Lot to digest here, but This caught my eye.....
"At idle seems to drop cylinder #2 50% of the time."
Is this with auxiliary tank setup, or with bike tank/petcock?
If latter, be suspicious of vacuum petcock- mine failed like this fouling #2 plug especially at idle.

[RedBaron]

That's a good thought Tom. It's with an auxiliary tank currently, a motion pro unit I've had for years. I had the same problem once way back when too! Despise vacuum fuel cocks. Your thought made me think though, I've had the vacuum hose clamped but I'll double check its condition when I get back to the garage. I can't think of much else that's specific to that cylinder, maybe something will come to me on the way. Thanks for the input Tom, I get so focused sometimes I'll miss the forest for the trees. Helps to have outside input.

Well, headed out to change carbs, examine vacuum hose, possibly swap air cleaner, double check manifolds, etc. It's embarrassing when I get to the point that I start swapping parts around but this bike has a way of doing that to me.

Had a mouse's nest blow out of the pipe after I installed the original. Surely that little >^*%^#@ didn't stop up the header or cross-pipe? Crap. I'll check it too.

[RedBaron]

Well, all is well again. I'll sync it up after I find my little adaptors. May play with the jetting later but she seems to run pretty darn good.

I didn't notice anything throwing the carbs on, but I did disassemble the old ones afterwards and the needle jet on number 2 fell out as soon as the main was removed.

Now to sort out this slow tach. Fixed it once back in the day but fml can't remember what I did.

[tom203]

Yeah, this switching stuff around gets confusing. Once you feel like you got a mechanically decent carb rack, I'd work with it. I'd pull carb rack , orient it as on bike, use your aux tank to feed fuel and make sure that float needles are holding fuel back,especially on #2. Then go from there.
since you clean carbs regularly at work, I imagine you're using ultrasonic methods?
The stock intake setup needs a filter element and tight airbox to avoid mid range stumble with the CV's

edit. Just caught your update-yeah for progress!

[RedBaron]

I wish I had an ultrasonic cleaner. Had one at the dealer in Florida but haven't had one at any of the places I've worked in NC. It's definitely on the want list if I ever buy the shop.

Honestly we just use Yamaha cleaner mixed 50% with water for heavy dipping if necessary. Mercury Powertune (engine decarbonizer) for most jobs (A spray, but if a floatbowl is filled with it it works awesome as a mini dip). Old float pin wires, old Yamaha shipping tag wire or loose wire brush wires to clean stubborn orifices, with contact cleaner or compressed air for verification. About 90% of work around here is ATV stuff anyway, singles are pretty easy to knock out quick enough for decent hours.

Yay progress! lol

[tom203]

Mercury power tune- I need to clean out a two stroke outboard that hasn't run much in 4 years ,so thanks for tip. Since you work on atv's (and know about the SH-775), try to keep us posted on what critters have discovered series r/r's.

[RedBaron]

If I spot one I'll post what I find, though I avoid Polaris products like the plague lol.