just got a 1985 GS550E (-ES?) and idle issue

[dueller]

alrighty folks, back for some help. i've gone through the carbs/boots/valves/oil/brakes and got everything cleaned up and ready. got the carbs back on the bike, but i'm not sure if i've seated the intake->carb boots properly. they don't seem to want to go on any further, but still seem to be unevenly seated on the carb.

other than that i got the bike cranking last night, and barely got it fired up after a bit of fiddling. it ran rather... strangely... lots of smoke, so i shut it off right away. does this mean it's running rich at idle? it seemed to rev fine, but sitting under 2k rpm it was definitely not happy. i currently have the idle mixture screws set 2 turns out, should i go further as a starting point?

You need to do a good vacuum sync set first. Then mess with your idle screws. Yours kinda sounds like mine. I can't seem to get an idle under 2500RPM If I get it to idle lower it will usually just die off within about 10 seconds. I think I have an air leak. Getting new intake boots (mine looked okay when I took the carbs off but after putting them back on I noticed cracking develop. I have new ones coming in the next couple days. Will let you know. I also have to do a vacuum sync.

also, i have a small gas tank leak that i attempted to fix with some "gas tank sealer" epoxy stuff. doesn't work for $h!7. the gas soaks right through it. any suggestions on how to approach this? or is it just easier to get another gas tank?

I used JB Weld on mine. Holding fine a couple months later. Someone had tried patching it with some kind of clear epoxy before but that was peeling. I just hit the area that was leaking with a wire wheel and then wiped it down with some acetone and then applied a thin layer of JB and let it dry overnite and voila! Fixed. If you are doin your tank, I have heard that the Kreem product to line your tank may not be the best thing for it! So beware. Most seem to swear by the POR-15 method.

[Dybz]

ok, figured out all the little issues it seems. got idle steady at 1150-1200 rpm, so i'm calling it quits there lol. i'll run out and try to find some jb weld, hopefully that'll fix my tank issue. if not, i'll just get the new tank and get everything seated a bit better i'll do some last fine tuning. thanks to everyone for their help.

[Dybz]

how "synced" should the carbs be? i have them synced perfectly at 2000 rpm like recommended by bikecliff's DIY, but when i drop the rpms to the idling 1100-1200 i have the left bank sitting about 17 while right bank is closer to 18.5.

here's where she sits now:

http://www.youtube.com/watch?v=GwkuCMMLbZY

[skreemer]

how "synced" should the carbs be? i have them synced perfectly at 2000 rpm like recommended by bikecliff's DIY, but when i drop the rpms to the idling 1100-1200 i have the left bank sitting about 17 while right bank is closer to 18.5.

here's where she sits now:

http://www.youtube.com/watch?v=GwkuCMMLbZY

that's a dang good idle, a mile better than mine usually was. I'd call it "done".

[Dybz]

so thought i was in the clear with the idle issues, but guess i'm not quite there yet. the jb weld is holding on the gas tank, so i took it out for a spin. it moves fine, but idle still kinda sucks. after a bit of riding, the bike started to stumble a stops again and i'm not sure what to do anymore. it seems synced, the idle mixture seems tuned, but it still sometimes seems to have a misfire at idle once warmed up fully. any suggestions on what to chase after?

[dueller]

Haven't done mine yet, and never done it before so be interested in the answer to this question. Someone else will have to answer that one

[Dybz]

heh, well just rode around for a good 30 minutes with plenty of stops (live in the chicago, so caught nearly every red light). bike had weird stumbles here and there, but ran like a champ. i know we shouldn't say "good enough is good enough", but i'm saying "good enough" for now. once i have some more energy i'll get after it and maybe tweak a bit more, but it seems to run well. good transition from idle to part to full throttle. maybe i just need some new spark plugs... i checked when i just got the bike and they seemed to be in good condition, but i might have killed them during the tuning lol. will check tomorrow.

[Dybz]

well looks like i lied about it being good enough. rode around today for ~1 hour and bike started dying on me. twice at lights it just died, and not from me applying clutch poorly, just idle idle sputter sputter die. so any ideas what can make a bike run fine for a good thirty minutes, but die after 60 minutes? definitely sounded like it was knocking before it died. barely got it started after both times.

[cowboyup3371]

Check your mixture screws...sounds like it's running lean.

[FiremanBob]

Am most interested in this thread as I'm having the same problem, especially after the bike has warmed up. At first I thought the clutch was dragging, but it happened in neutral at a stop sign yesterday.

I plan to do the coil relay mod one evening this week, and am hoping to avoid having to pull the carbs. Step 1 will be a heavy dose of Techron in hope that it will unstick anything in the carbs. But I'll do whatever it takes to make this bike run smoothly and reliably, as it is for my GF who is a new rider and doesn't need the distraction of fiddling with the mechanism while riding. I have to remove the valve cover to check the reinstallation of the tach gear, so while the tank's off perhaps I'll go through the carbs anyway.

[Dybz]

Check your mixture screws...sounds like it's running lean.

i'll retune them, but why would it start running lean after warming up? seems like it should have more trouble right away while the fuel is still on the cooler side and not vaporizing as well, no?

[cowboyup3371]

Not really. I had the exact same issue last year where the bike would run great cold and by the end of my 22 mile ride to work or home it would die out. My screws were at 1, 2, 2, 1 or so at the time. Have all of them now at 2 1/2 or 2 3/4 turns out and it runs great.

[Dybz]

Not really. I had the exact same issue last year where the bike would run great cold and by the end of my 22 mile ride to work or home it would die out. My screws were at 1, 2, 2, 1 or so at the time. Have all of them now at 2 1/2 or 2 3/4 turns out and it runs great.

k, i'll take a ride tonight after work to warm it up to the point where it's nearly dying and try to retune in that condition.

[Dybz]

got out of work a bit early as i have a doctors apt in a bit. rode the bike around until it started doing the sputtering like before. got it into the garage and went at tuning. it was still kind of sputtering when i was making adjustments, but nothing fixed it. i got it a bit better, but it still died eventually. the bike simply seems to be over-heating after a long ride. i understand you should use a fan and all to cool it while tuning, but this still happens on the road. if i let it cool off for about 5-10 minutes in the garage, it runs fine for about 10 minutes then starts sputtering again...

i used diesel oil, and it definitely has the proper amount in there. is it possible that the electrical system is actually what's overheating? and not the engine?

[BassCliff]

Hi,

I haven't been keeping up with this thread, and I didn't take the time to read the whole thing. So forgive me if you've already considered the following.

I really don't think engine overheating is your problem. It is possible to have a thermally intermittent ignition component, like the igniter or coils. But check the simple stuff first. Is the gas cap venting properly? It can be disassembled and cleaned. Make sure the hole in the filler neck is clear. This can get clogged when you paint or seal the fuel tank. Make sure your fuel line has no kinks and no "uphill" path to the carbs. Inline fuel filters are usually frowned upon because of the fuel restriction they can cause.

What do the plugs look like?


Thank you for your indulgence,

BassCliff