Alright now I'm gonna put all your gray matter to work for me. I have a 1995 GS500E that is giving me some issues as of late. The other day when getting ready to leave work I started the bike let it warm up and left, well I try to get on it a little at the first stop light and nothing! It was as if there was a restrictor plate preventing my engine from revving, it finnaly starts to climb th scale slowly and is backfiring off and on thru the whole ordeal. It continues to act like this thru all 6 gears and finnaly stops when I get to cruising speed. I didn't take a look at it that night when I got home (I know, but I was tired and a little frustrated). So I go to start it the next day and its very hard to start and stay running. so I stop it and take the plugs out. here's what I found, the left plug was very black and smelled of gas and the right plug was a nice brown color like a proper spark plug should be. Also I noticed that there was some gas leaking out of the cylinder around the exhuast pipe. I have already ordered some fancy-pants iridium plugs for it, but why is there so much gas in that one cylinder and how do I fix this.
Thanks,
Aaron
My bike has done the same thing before. I think I may have left the choke on a little too long and it fouled a plug. As the bike is warming up, touch the outsides of the cylinders every little bit to make sure both cylinders are hitting. If one is cold it could be a fouled plug. Pull the plug wire on that cylinder and slowly put it back towards the sparkplug. If the cylinder starts hitting again then you just had a fouled plug. Check all your hoses to the carbs when you replace your plugs this time and make sure all the fuel is blown out of the dead cylinder. Good luck. But yu just love the little bike don't ya? And this forum too?
C.......
cernunos posted his excellent suggestions while I was working on my probably-not-too-useful treatise below.
Oh well - I'm gonna post it anyway!
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I'm no expert on fuel mixture issues, but let's work backwards from the cylinder.
1) Spark plug is black and "wet".
Hmmm, does the Haynes Spark Plug Chart (http://www.bbburma.net/Scans/Haynes_SparkPlugChart.jpg) hold any clues? I'm betting that your left plug looks more like the "Carbon fouling" example than the "Oil fouling" one, right? The carbon-fouled plug in the chart isn't wet, but how long can you expect liquid gasoline to sit under a hot studio light before it evaporates? ;)
OK, so too much fuel (or not enough air) in the left cylinder.
2) Just "upstream" is the intake boot. A leak here would cause a lean condition, not a rich one. Next...!
3) Ah, the carburetor. What could cause a rich condition here?
* Jets that are too large (Naw, they haven't
changed on you, have they?)
* Float level too high? (This seems like the thing most likely to affect one carburetor and not the other. Even though the float level shouldn't just change wat random, it's easy to check (http://www.bbburma.net/FloatHeight.htm). Give it a shot.)
* The spark plug chart mentioned "faulty choke operation" as a possibility. I've never heard of the choke working on one carb and not the other but it did say "faulty". :dunno:
* Anything else in the carbs,
Srinath? Slide not opening, perhaps?[/list:u]
4) The next item upstream is the boot between the carb and the airbox. Hmmm, is there a sock or something stuffed in the left hole in your airbox? :dunno:
5) The last component before we hit atmospheric air is the air filter itself. The Spark Plug Chart mentioned "blocked air filter" as a possible cause. But the filter should supply air to both cylinders equally - there's no provision for "preferential treatment".
I dunno ... was this useful at all? Hopefully it will trigger something in your mind (or someone else's).
You probably guessed it, but the fancy pants iridium plugs probably won't solve your problems.
In fact, I'd avoid putting nice clean plugs in until you've got the problem figured out (that is, of course, assuming you can sufficiently clean 'em using a wire brush and a compressor. If you suspect the plug, and want to try something else, get the stock NGK plug which is something like a dollar or two. Get it working good with those, if you have to.
If you mucked with the carbs prior to this happening, you might want to check that the washer on top of the needle valve (below the spring) is still there. I put mine below the needle valve when reassembling (on both) and had similar problems.
The float check is even easier than hella-easy, and I'd check is simply because it's so simple. A bit of aquarium hose and you'll have it checked in less than 1 minute in your first attempt :thumb:
OK my $$$ is also on stuck open float.
Cool.
Srinath.
Alright I believe I have the culprit at hand. I was messing around with the bike tonight at my parents house (my dad use to have a GS550E) and he [my dad] and I were going over what it could be when I started it up, well I removed the spark plug boot from the left cylinder (the one I am having issues with) and the bike continued to run as if I hadn't done anything to it, so I plug that back up and do the same to the other plug [the right side] and the bike dies. Now that leads me to believe that the left side is not getting enough spark for it to ignite the fuel. I rode it home and when I got here repeate the sequence with the plugs, but now the bike stays running no matter which one I pull, as if the coil on the left has started working somewhere on the trip home. I am going to swap the spark plugs around tomorrow before I head to work and see if the problem moves to the other cylinder with the plug, if not I am going to swap the coil packs around before I head home from work and also see if it follows the coil instead. Tell me what you guys think about this and if my diagnoses is correct. Also I did a search about the coils and found some posts very much like mine, one mentioned replacing the coils with Accel coils, anyone have a part number for the piece?
Thanks for all the help guys, hopefully this will help other people who may be experiencing the same issues from thier bike. I'll keep y'all informed as to what happens tomorrow.
Alright well the problem did not follow the coil or the spark plug. The next thing up the line is the ignition "brain" I guess. Does anyone have one I could "borrow" for the next step :) .
You can't test the
ignition control unit ("ignition brain") except by replacing it, but that can be prohibitive (cost-wise and/or convenience-wise) ... and unproductive. Personally, I suspect the
pulse generator coils or the wiring and connections that lead to them.
I'll tell you what I recently told
caddmonkey1 in the Rejet questions (http://www.gstwins.com/forum/viewtopic.php?t=10398) thread:
Quote from: Kerry...try giving a read through the first two pages (!!) of the old thread Narrowing down the problems to a broken bike. There are a couple of detours and delays in the "narrative", but by the time you reach the checklist at the bottom of the 2nd page you should have a good feel for why you're checking the listed resistance values, and where to check.
Let us know if you get stuck, or what your results are.
If the tests don't show a problem, you're not out anything but an hour or two of your time (as long as you already have a multimeter). But I'm betting you'll find something....
(Kerry crosses his fingers behind his back. :roll: )
Update:
Alright I tested the wires coming from the signal generator for continuity up to the ignition box and the tested good. Unfortunatly I didn't read as far down the other post as I should have or I would have tested the wires for resistance and also the connectors. I just tested the connectors for continuity. Oh well hopefully it will be sunny tomorrow so I can ride it in to work and perform the correct testing procedures.
I work as a mobile electronics installer so thankfully I can pull the bike in and work on it when we're slow. I also left my multimeter there, so no testing for me tonight, and unfortunatly I only have restriced acces to the web so I can't look this stuff up at work (would have helped today).
:x :x :x :x :x
It's always something! Alright so I decide to work on the bike tonight after not riding it today. I take the tank off and everything to check for anything suspicious looking around the carbs. I don't see anything out of the ordanary so I put the tank back on and then proceed to tear the fuel lines to bits trying to get the dry rotted pieces of crap grrrrrr :x . Okay I'm better now.
But to get to the update on my problem I checked all the connectors for resistance and they all check out fine. So I tried to start the bike with the good cylinder plug wire removed. It starts up if I give it gas but will not idle on that one cylinder (the left side). It will however idle on the other cylinder (the right side) if I remove the left plug wire. So I'm begining to think it might be fuel related.
Thank you for your help so far guys. I might be on the way to getting it fixed with y'alls help.
By the way I need new fuel lines. do I have to get the Suzuki parts or can I get some standerd fuel line and cut to length.
It sounds like most (maybe all?) of the testing so far has been electrical. (I nudged you down this path because of the "running on one cylinder" symptom. Sorry it didn't lead anywhere....)
It occurred to me that you haven't mentioned whether you have cleaned the carburetors. Perhaps you're just getting started down the fuel system path? Let us know what you've done so far in that area.
Yes, you can buy fuel hose in bulk and cut it to length. But take along one of your current hoses -- a lot of the auto stores seem to only sell thick-walled 5/16" hose, which can be a bear to fit; especially side-by-side at the fuel tank petcock. (The 5/16" inner diameter isn't so bad, although it's a little larger than stock. It's the thick wall that's hard to work with.)
Probably the best message thread about fuel hoses is A question to the GURUS (http://www.gstwins.com/forum/viewtopic.php?t=7256).
Update:
I bought the gas line and installed it the other night, I also added an inline fuel filter while I was at it. While I had the tank off, oh just a note watch out when you disconnect any fuel line or it'll flick gas in your face(it burns your eyes like a mother :nono: ).
I decided to take the carbs off and look them over, I didn't notice anything unusual, no rust stains or trash in the float bowls. No cloged jets.
I finaly got everything back together and found out my fuel filter was leaking, so I had to take everything apart to get to it and change the line. The fuel filter as it turns out was made for 1/4" lines instead of the 5/8" I used for the rest of the system. I used the transparent blue lines they had at the motorcycle shop and T style hose clamps specificly made for fuel injection lines.
But the unfortunate thing is I still have the one cylinder problem, I still think that it has something to do with the Ignition Control Box, so I think I'm going to take it to the Suzuki dealer and see if I can get one of thier techs to look at it and give me some good news, It might involve a little 12 pack bribery ;) but I'll get it fixed somehow. I'm still waiting on my Haynes manual to get here so until then I'll just ride it the way it is.