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I have a 1981 GS 550t that will start right up some days and do nothing on other days. Just bought bike has electronic ignition. When riding I notice when cold it might only be firing on three cylinders. When I pulled off the tank I noticed that the one ignition coil said good on it,the other nothing. Any ideas,help.
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If it was your coil, it would only be firing on two cylinders, I believe. When you say "do nothing" does it crank and not fire, or just sit there? Any other issues with the bike? What have you done to the bike (carbs, plugs, etc.)?
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I would start with the easiest and most obvious. Clean fresh gas, Is the petcock working properly and delivering plenty of fuel to the tank. Loosen the carb bowl drain screws and make sure they all 4 have fuel in them and have no traces of water. Drain them into a clear glass container and look for water bubbles in the bottom. Are the plugs gapped correctly and clean or new?The easiest way to check for high voltage from the coils is an inductive timing light. Simply clamp onto each plug wire and crank engine and point the light at you and you will see a steady flash on each plug.After that is a compression test. I know this is a lot of info to digest at once but If all these things check o.k., It's time for a carb rebuild. I hope this helped you!Comment
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Okay the tank has fresh gas,somedays the bike will start right up and has plenty of power for what it is. Has new NGK plugs which I put in,air filter cleaned,frsh 10w40 in crank case, sometimes it won't fire at all when it is cold or when it was shut down warm for a fuel refill. No spark at all. Very strange I have to say,I do not think it is fuel related at all. I am getting all kinds of answers,ignition coil,rectifier,pick ups off the stator,ignition switch, help thank you. When the bike runs right it moves good with a 4 into1 header that was on it.Originally posted by Fishman View PostComment
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All gas is fresh,new plugs,air filter cleaned was not even dirty. I believe it is electrical because the bike will start and run fine and then if you stop sometimes it cranks but still won't even fire and I checked for spark while it was warm with a screw driver in the plug boot up to the plug nothing it cranks fine. It will do this cold to. I have been told ignition ciols,rectifier,pick up coils on the stator and so forth. I do not want to just start buying stuff and replacing by process of elimination. Thanks for your help.Originally posted by lrburke View PostComment
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550t
Hello, I have same model bike as you. I to have been having a [electrical orfuel] problem. at WOT, bike pulls until 5k rpm then goes into fit sounds like ive hit rev limiter. if i use less throttle above 5grand it starts to clear.last year i put stage3,k&npods,mac4in1.Bike ran great untill middle of may then started having this prob.I replaced petcock due tu leak. synched carbs valves set 1.500 miles ago.replaced wires,boots this seemeed to help. I did coil mod due to 9.8v at coils.bike runs good until 5krpm.but mine has always started. ive been told possible igniter box.suzuki used either ND/electrics or KD/kocusan denki.what is on yours. p/o must have known problem to replace one coil.looking at dyna s ign/ does away w/igniter box. to see what this does go to www.gs-classic.de/index1e.htm bablefish to translate to english click on tech or tips ignition igniter shows the inside box. to much to go wrong. i believe system updated in 82, not pos. good luck. SAN
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Same deal here
My bike is doing the exact same thing including this morning. Ran fine yesterday but then it is cold outside this morning and it will start for about a split second and then has this bogging down sound where no throttle or choke helps. after that second of bogging down nothing will work you can crank away till your battery dies. I usually either wait until when I get done with work and it is warmer out or else end up bump starting it. I am not sure what it is I am planning on testing a lot of stuff over the weekend... So you are not alone.Comment
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Doggies, I think you are on the right track in thinking it's electrical, but you definitely need to check for spark from all four plugs. Check it when it's running good and when it's not. It's possible you have an intermittently bad coil which would show up as two plugs sparking and two not. Test in a darkened area because the spark can be hard to see.
I don't think the rectifier or the stator could be the cause of no fire, as they are only responsible for charging your battery.
Do you have a multimeter? If not, get one. Harbor freight $4 one will work fine, or go to Sears and get a $20 one. Although this very likely isn't your problem, you can check battery voltage when the bike is off (should be higher than 12.3 volts for any reasonable battery) and when it is running (approach 14.0 volts at 5k rpm). Those are the values on my bike, anyway, and are in line with what others are saying. Assuming this is ok, your reg and stator are ok.
Next you can use your multimeter to test for continuity in your switches. You will need a wiring diagram for this. If you don't have a Suzuki manual (you do have a Haynes or a Clymer though, right?) go to BikeCliff's website and download the pdf. http://members.dslextreme.com/users/bikecliff/
It's really easy to do, and it's how I found that my starter button was bad.
You can also use the meter to measure resistence in your coils and spark plug wires. That will tell you if things are going south with them.
There is also an ignitor/cdi test described in the Clymer manual, but people have reported mixed results. I don't think I would trust it after reading the procedure.
It still may be fuel related. Are you using the original petcock? Mine was bad and I bought a new one from Z1 enterprises. Make sure your vacuum line is intact. It runs from front of the #2 carb (left to right as you are sitting on the bike) and goes to the smaller angled nipple on the petcock. When vacuum is applied, gas flows when on the "run" position. I doubt this is your problem, but anything is possible.
If any of your electrical values (resistance, continuity, voltage) are out of spec, you've likely found your problem. Searching the website will get you lots of good advice.Comment
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Thanks pal
I checked the voltage when the bike is running with a good meter I have. I found that it is in the low 13 range,when lights are one the meter goes even higher. Now I took the tank off and saw the two ignition coils. One gas wriiten with a marker good the other it says nothing. I talked to a guy today who asked me how the fuses were and they look fine. I clean all wire connections with a very good electrical cleaner. He was saying somewhere there might be corosion,not evident that I could see. When it runs good it screams to red line no problem. Was there a rev limiter on these older bikes. Also could use a left side cover with chrome piece or just the chrome piece. I am keeping an eye on ebay. All letters were removed and bondod over no big deal. Need to get it up and running.I am in Broomall,Pa. know any good people out this way. I am 10 miles approx. west of west philly. Any comments fire away. Have a good night. I have a old 81' Xs eleven special thats been sitting in the garage as well.Comment
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Bike cranks and fire and runs good somedays and other times when you shut it down to refuel or for the night it won't start but cranks fine. One ignition says on it good the other says nothing. Has new plugs.Originally posted by Fishman View PostComment
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when you test the plugs by pulling them out. you should also look at the plugs for raw fule still sitting on them so to make sure or not if you are getting fuel.Comment
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It certainly sounds like you might have a bad ignitor. Very very likely that it is electrical. However, it isn't your regulator/rectifier or your stator, those look good from your test.
BUT, if you still have the original petcock it could be the problem. When running the bike it needs to be set on the "run" position. Prime is for a few seconds to "prime" the carbs before starting. Then return to "run" before cranking. If the petcock fails, it dumps gas at all times. Conversely, if your vacuum line is cracked or not attached firmly to the nipple on your #2 carb, the petcock may not flow fuel at all. You can test this by pulling the fuel line off the petcock (NOT from the "T" between carbs 2 and 3) and pulling the vacuum line at the #2 carb. Apply a vacuum to the tube either with a vacuum pump (Mityvac or similar) or just sucking on it a little. You shouldn't get any gas this way, but I recommend a clear vacuum line.
When the vacuum is applied and the petcock is on "run", gas should flow. Turning the petcock to "prime" should allow gas to flow without a vacuum. If gas flows all the time on "run", or not at all or stops when vacuum is applied, then you need to replace or at least rebuild the petcock.
I would certainly eliminate the petcock as a source of the problem before buying an expensive ignitor, IF you can find one on ebay.Comment
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