The bikes been running better then it ever has until a few days ago. Stopped at the store parked on a fairly steep incline got caught inside talking to a friend for a few minutes and when i left the bike struggle to start bogged hard trying to turn over and i could smell it was very rich. got it started and home and parked it. Went to leave for work the next day and the bike was leaking fuel out the overflow very rapidly figured i was silly and left it on prime, switched it back bike started and ran fine, smelled alittle rich but thats fairly usual. worked my 12hr shift and when i went to leave last night the bike bogged hard with the choke on, barely getting above 3k i released the choke and she returned to the usual idle. went to pull out and she bogged and died before i hit 5k pulled over, tried to restart the bike turned over again running very rich and wouldnt start. Let it sit had a cigarette tried again it started but the moment i tried to choke it she bogs and dies again. Im assuming either a float needle is stuck open just broken in general im going to pull the carbs on tuesday my next day off but does anyone have any ideas or things specifically i should be looking for/at?
Yeah, definately sounds like a needle valve seat issue... I'd turn the tank petcock off until you are able to check it out. You could confirm its carb/fuel issue with a carb drain check (clear U-tube method), and rule out spark, but there is a BIG finger pointing to the carbs anyway since you just had the overflowing problem on prime. Since you'll have them off the bike, you might as well clean up and replace and rubber/gaskets/o-rings in there if you can.
:cheers:
- Bboy
If you need the bike for work or something you may want to source the orings first they can take a few days to come in.
FYI.
I am at work so cant check the parts diagrams (youtube is blocked).
To rebuild both its probably 30-40 for both sides most all orings. I imagine the jets can be cleaned and if the needle is good that can be reused. Just the orings get old and leak after a while.
Of course record how many turns out each carb is etc prior to taking apart so you can reset there if needed.
i have my very reliable daily driver of a car so the bike isnt a necessity for anything more then my sanity :) but the carbs have been a major issue on this bike the entire time ive owned it, it started with just high speed bogging which i assumed was a petcock issue, swapped to an '04 petcock and saw little to no change essentially every issue this bike has ever had has been ridiculously inconsistent. Some days it runs great other days it wont run at all, ive been putting off a full carb tear down for WAY to long so i guess its a good time, ive gone threw the wikki and youtube threads as far as disassembly and cleaning and i am decently mechanically inclined but my carb knowledge is very lacking, what source do most of you use for seals and orings? i know theres the general rebuilds on ebay i see them very regularly, and there is a good suzuki shop maybe 15 minutes from me that i used for most of my front end replacement parts after the wreck. But any where more direct?
I use:
www.rockymountainatv.com (really like this store)
or
www.Bikebandit.com
Most times I use my local motorsports dealer, we have 3-4 locally but this is closer to my place.
www.us27motorsports.com
I do ship to store to save on shipping, pay the tax and help the local store out.
I didnt do a rebuild kit. All the metal parts you are probably good on. The orings need to be replaced. I tear down and clean then place my order. Then once its received wrap the carbs up.
I have done maybe 7 carbs total in the last 2 years. Take your time, take pictures.
I use an air compressor and carb cleaner to clean the jets, etc. I also have used a sandwich tie (metal) to knock out the jets, be careful not to scratch the brass.
Its honestly not that hard if you are just returning to OEM specs.
DONT blow compressed air through it with the diaphrams, etc still installed.
Unless your "T"'s are bad no reason to separate the carbs. If you do separate the carbs the carb that vents to the petcock is on the left.. the right carb has the vent nipple but is blocked off internally so make sure you have them marked left and right.
If you are mechanically inclined this will be a few hour project and then done. You will see a huge difference in the performance.
got them off and apart now, orings all look good i think the left side carb float needle slipped off the tab... (would that cause the flooding and drowning?) it would make sense bc when i pulled the plugs only the left side looked wet the right was completely dry. i rebent the needle hanger back to matching the opposite (it was bent open a bit more and when i pulled the floats the needle didnt come up with it on the left side carb, right side seemed fine...) cleaned the jets and bowls now im heading back to reinstall them.. we will see. fingers crossed i wanna get back on this thing.
reinstalled (holy chit getting the carbs back into the airbox is a pita!) bike turns over freely but wont start. tried in both prime and res. battery died before i had a chance to trouble shoot much more im going to charge the battery and try again tomorrow.
tabs don't.necessarily.match. you have to check fuel height out of carb drain hoses.
also don't forget the on off under the tank (petcock). if you left that left to right (horizontal) its off.
there is a spring inside thqt needle valve. If its not functioning then you will need to replace or separate it and clean the brass and spring. it needs to spring up.
i reset the tank petcock to on but when i pulled the needle seats i didnt see any springs, was just a simple brass fitting with oring like shown in the sticky post. maybe im not picturing what you're describing... i know theres a spring on the needle from the diaphram?
hi there,
i've been through 3 sets of carbs now... just dont ask... hahaha
but fuel out the overflow? now someone feel free to correct me if i'm wrong here but the gs doesnt have an overflow from the carb, it has the vacuum line to the petcock, fuel line into the bottom and a breather out the top, which obviously doesn't attach to anything, often confused for an overflow.
now i cant comment on the inconsistency of the issue but if you have fuel coming out of the breather it means it's likely that the needle seat isn't seated properly i.e the o-rings on the jets arent doing their job
well thats from my experience anyways, it confused the hell out of me for days, learned how the backpressure worked whilst going over and over diagrams haha, the way i see it is you can either replace the o-rings or replace the seats. secondly i would check the needles are in decent condition.
hope this helped man.
B.
overflow from the airbox :X was what i meant, how exactly does one diagnose the needles? i had both out today both seemed fine but this bike is 20 years old... im assuming the needle itself wears in the float seat to the point it can no longer close the hole at the bottom of the seat causing the overflow and bad AFR? i inspected both needles but i dont have a micrometer nor do i know the seat hole tolerances to make a judgement are there certain characteristics i should be looking for on the needles themselves to deem them good or bad?
Quote from: JollyRojer on June 25, 2013, 07:08:10 PM
i reset the tank petcock to on but when i pulled the needle seats i didnt see any springs, was just a simple brass fitting with oring like shown in the sticky post. maybe im not picturing what you're describing... i know theres a spring on the needle from the diaphram?
Float assembly has been removed.If the needle's seat O ring doesn't seal tight,it will flood the crank case with gas.
(http://i205.photobucket.com/albums/bb17/ben_2_go/Motorcycle%20Stuff/Mikuni%20BST33SS%20Carbs/floatneedleseat-1.jpg)
Float assembly.If that O ring or needle doesn't seal tight,it will cause running issues and flooding.
(http://i205.photobucket.com/albums/bb17/ben_2_go/Motorcycle%20Stuff/Mikuni%20BST33SS%20Carbs/floatandneedle2-1.jpg)
see the float needle in the above pic?
your loking at the bottom with the rubber point. the other end has a little clip (don't let this fly off). you take the clip off and there is a little piston and spring. clean that up. maybe some fine sand paper around a toothpic, etc. then clean the piston. old gas with ethenol gunks these up.
put the spring and piston back in and snap the c clip back on. then use your finger and make sure that piston is bouncing back up. if it is then it should push against the tab on the floats and help your issue.
now also make sure the floats and that stem on the floats are seated tightly and those orings are good.
again this is my understanding when you said the one side was not springing back up. that piston and spring is what allows that.
make sense? I am on my phone but I can get a pic tomorrow if you need of an extra one.
after you do both these.
put airbox on carbs and install all as one.. its way easier this way then.lining up boots. either funnel or hook up tank and then check the float height on both carbs with a clear hose out of drain screw. (search float height if you dont know how).
once that's done button her up and she should fire.
from there check it out and maybe a carb synch is in order. if you need a how to.build on that, ask. I can link it tomorrow. there is a better one then the yardstick method and just as cheap.
oh and needles (not needle valve). those probably do wear, but more likely they will be fine, unless bent. I doubt the needles are an issue, bit if the above doesnt do.it you could pull them and make sure they roll ok on a glass table. you'll know if they are bent. someone with more experience than me can chime in if they actually wear out... i mean it would take forever..
ah ok gotcha that could be the issue, i pushed on the needle with the clip off and it didnt move or bounce at all, i did however get the bike started today and it ran decently until my ride home, its a pretty consistent 55 and about a mile into the ride home it started bogging and jerking pretty hard, i got it home at about 45 the majority of the way but it still sounded bogged pretty good then it would fire and jerk forward a bit now that its home at least i can take it apart more comfortably instead of the gravel at my work and i wont be so rushed, im going to rip it back apart on saturday if i can recreate the problem again tomorrow morning. ON a good note the bike from 0-55 is responding ALOT better to my throttle then previously.
btw big thanks for your quick responses snake and dedication to helping me fix this i would be so far in the dark without the help lol.
hey no problem, keep us informed. that little snap ring can.fly offi have lost them on other carbs.. then your buying the needle and that's probably $8-$20. so do it inside once you the needle out or in the bathtub so you can find it.
Don't forget the plug in the bath tub though ;) :thumb:
Why does this man post irrelevant things in a high technical thread on our forum? The thread is so frequently disrupted by the man. Is this the way this forum operates? I am accutomad to moderation in technical areas. Can some moderation be organised?
..... Hmmm ... Anyway ... The plug in the bathtub mentioned by Snake ... Because those little widgetty rings could easily get lost down the plug hole ... :thumb:
I have taken the needle valves apart in my garge and I listen to my headphones while working.. fat chance of hearing metal hit the ground, especially that small of piece with headphones on. :technical:
I would suggest any small, non carpeted room for this. And the plug is legitimate.. it could with murphys law would go down the drain.
Quote from: Vindicate on June 27, 2013, 04:00:14 AM
Why does this man post irrelevant things in a high technical thread on our forum? The thread is so frequently disrupted by the man. Is this the way this forum operates? I am accutomad to moderation in technical areas. Can some moderation be organised?
Bwhaha noworries mate, he posts like that all the time :icon_twisted:
ive just about got them off again, quick question before i mess something up, with the clip off does the needle piston twist out or should it just move freely out of the inside of the needle?
pulled the carbs again, cleaned everything, again. needle pistons seemed to be working correctly. checked the gap on the plugs. put everything back togther, bike fired right up, reved fine, took it up and down the street 2ce and it started bogging again, pulled into the driveway and it choked and died didn't even make it up the hill. pulled the plugs and i found this on the left side...
(http://i29.photobucket.com/albums/c287/Jollyrojer/80F65DEE-DDAD-4AB7-B231-4CBF5C0CD6F2-3114-0000011E554DDF24_zpsc30c0b8a.jpg) (http://s29.photobucket.com/user/Jollyrojer/media/80F65DEE-DDAD-4AB7-B231-4CBF5C0CD6F2-3114-0000011E554DDF24_zpsc30c0b8a.jpg.html)
what in the world is going on with this thing? im starting to wonder if im better off kicking it over and burning it :*( its performing worse now then before, bogging at anything more then 5k and just dieing....
What plug are you running?
Those springs just pop out with the little clip missing, but you probably know that now.
Valve adjustment been done?
Carb sync?
I cant recall.
carbs are synced but no valve adjustment yet... im worrying it is a valve, the bike has been idling really high once it warms up (which ive heard is caused by an air leak around the intake boots?) the bike also when warming up will make a decently loud pssshht noise like a blowoff valve and drop in rpms for a split second every minute or so. sounds like its coming from the top end above the exhaust, i always figured it was a worn out exhaust gasket, but i replaced both when i wrapped the heads and it still occasionally does the noise.
the plugs are NGK's i believe? they came with the bike when i bought it.
well get 2 correct plugs and.gap.correctly. i changed the plugs on my wifes car.today and one literally came out of the package like that.
you have no idea what the prior owner did, so start over on plugs.
Get some new plugs, check the gaps before you install them.
I can think of a few things possibly going on here.
1. Problem in the bottom end causing the piston to travel too far and contact the spark plug. Bad news.
2. Detonation caused by poor fuel, timing set incorrectly, bad spark plug, or other issues - Replace the plugs with the correct ones (cheap test), do a compression test, check the timing rotor and timing chain to make sure they are configured properly, drain and replace the fuel.
Thanks guys glad someone else is helping here. I am not the pro, but I am willing to admit it.
Know a few things, but then depend on the forum after that!
Let us know OP!
I'm not an expert either, but I'm mechanically inclined, have some experience with GS, and I'm decent at googling. :)
righton thanks a bunch for the help guys, i thought i had it after the first carb rebuild but its being a pester, im picking up new plugs around noon tomorrow i will pull the tank and drain it completely, refill and retry. if its still not working i will check the valve gaps, and replace shims... if its still giving me problems im going to post it on craigslist or shove it off a cliff :D
don't forget to check timing chain.. you can do that when you check the valves I believe.
so its pouring today but i got new plugs got them in. bike refuses to start with the choke on, remove the choke bike fires up, idling extremely low the moment i touch the throttle at all it dies, let the bike warm up for a few minutes, touched the throttle and it hesitated a bit, reved to just under 4k then dies again. restarted the bike let it warm up a bit but it refuses to rev passed 4k... i did drain the fuel and put new fuel in but with the rain i wasnt going to open the top end up and start checking valves and timing chains. hopefully on Thursday ill get some nice weather in the morning so i can pull it and check it out. what small things am i looking for timing chain and sprocket wise?
Man sounds like a fuel issue there, really does.
Positive you have the fuel lines on correct from petcock to carbs?
No missing orings carbs re assembled correctly? Inspected and cleaned all portions of the carbs? Those ar passages can get some gunk in them and that will throw the whole thing off.
Sounds to me like the bike is running rich, and maybe only firing on one cylinder.
Quote from: RossLH on July 02, 2013, 06:07:43 PM
Sounds to me like the bike is running rich, and maybe only firing on one cylinder.
this is exactly what it sounds and feels like... but cant figure why. starting to lean twards a stuck valve or something along those lines...
when i had the carbs apart the first time i followed the quick clean video on youtube, the second time i had them apart i pulled the diaphragms and emulsion tubes and needles and literally cleaned EVERYTHING. checked all the orings and seals everything seemed good. (one thing i did notice was the floats where noticeably a lighter color... dont know if that means anything) I guess when i have them apart tomorrow i will double check everything and then get a quick sound clip for you guys. IM positive the fuel lines from tank to petcock and from petcock to carbs are right, i double and tripple checked with the diagram in front of me lol.
Check the float heights with a clear tube. Make sure they absolutely no higher than the float bowl gaskets.
weather and work have been killing me (i work 60hr weeks i get 1 sometimes 2 days a week off and the last 4 have been complete washes with rain) doppler says only 40% chance after 12 tomorrow so hopefully i have a chance to tear this thing back apart again... im going to check valves, timing chain and gears as well as total float height a pray its somthing carb related and not top end wise :(
Why don't you start with the simple stuff first? Check the floats with the tube, takes minutes and no disassembly required. If one of the floats is stuck open or not sealing, that side will run way too rich, possibly even too rich for that cylinder to fire.
Don't get too ahead of yourself. Rule out the simplest fixes first. One step at a time.
what is the tube ID for the float checks? i will do that tomorrow first thing, most of the advice was based on the fact that pre original cleaning the bike was flooding which was obviously passed a float issue, but since cleaning it seems like ive removed that one issue but now have 3 more, its just a narrowing down now but without riding the last 3 weeks ive been going crazy. im more irritable at work and i miss it like nothing else, getting on my bike was my way of getting away and i feel like im stuck without it :( tomorrow is supposed to be nice so wish me luck :)
Quote from: JollyRojer on July 12, 2013, 09:11:05 PMmost of the advice was based on the fact that pre original cleaning the bike was flooding which was obviously passed a float issue
Flooding is very much a float problem. That said, I want to say the ID is 3mm, I use a 1/8" tube.
"Flooding is very much a float problem"
Not entirely true, i had a over rich/flooding issue with my 89 and the petcock diaphram had ruptured sucking fuel straight into the intake at full vacuum