Kirjoitin aiheen englannin kieliselle fooumille gstwins.com, enkä valitetavasti ole jaksanut kääntää tätä suomeksi. Pahoitteluni siitä.
I bought my GS500E -99 in the summer 2008. I was going to get a driver’s license but other things came up. Now I’m finally getting my license next month. First year my bike worked perfectly. I didn’t know much about how the first owner had tuned the bike. I bought it from my uncle, who didn’t know anything about it either. It had a new exhaust pipe, that’s all I knew. Readout is 33 000km
After the first standing period, there were no problems, except for cold weather, but soon I realised that after 1 hour of warming up, the bike worked fine. I made some bad mistakes, for instance at the standing period, I left the bike without a stable for about three months and didn’t do any recommended preparations, just left it for 8 months.
After the standing period, I left the bike for a long time, I’m not sure for how long, I didn’t use it for about 4 months. This is probably when the problems started, but I just thought that it was the cold weather again. I didn’t drive enough to find out, cause I didn’t have a license. I just drove a few hundred meters every month, so that the bike wouldn’t stand too long, without driving. At that time I cleaned carburettors first time, and I think it possible that only problem at this time was cold weather and by opening the carburettor I caused this whole problem. But its just one theory.
I did the same for the next standing period. No preparations. The bike started great and I drove it home. Later when I started using the bike a bit, to avoid it standing too long without using, I realised that there was something wrong. At idle speed RPMs jumped from 1100 to something like 2000-3500, maybe even 4000 sometimes. After some time RPMs went back down. And it did that all the time. Usually it calmed a bit when the engine started to warm up.
Later I found a new symptom. When I opened the throttle, the engine stalled. And it worked a bit better with choke on. First I changed the oil, oil-filter and the sparkplugs. That was all I knew about bike maintaining. And I bought 'Haynes servise & repair manual Suzuki GS500 Twin'. After doing some reading I thought that it must be about carburetors and I opened it and cleaned it 2 more times, without any success. After changing the fuel hoses, the problems just got worse and later *I realised that my fuel tap was broken or stuck. I cleaned it and after that it didn’t stall after giving throttle anymore. But I still had the RPM jumping problem. I tried to fix the idle speed, but I already knew it wouldn’t help.
I end up with idea, that fuel-tap was broken, when my bike suddently started to drop speed at high speed. In the end it stalled and I was unable to start engine. After wiegening the bike to hear if I had fuel in tank, I wasnt sure if there was gas or not, so I turned the tap to RES just in case. After that bike started and I thought that was the problem, but at home I checked that there was still enought fuel for driving. Next day After starting engine it first rolled like 10seconds before stalling, after that about 5seconds and then only 3 seconds. After that it didnt start at all. and I checked if there was fuel in float chamber. There was some fuel, but I didnt realise that the level was too low. I realised the cause when engine started to work well, when tap was set to PRI. Now after cleaning bike works well as it does when set to PRI. So I belive it was one reason to bad functioning, but im not 100% sure.
After all this maintaining my carburetto probably lost its fuel/air mixture synchonisation or some o-rings or the diaphragm might have got in bad shape after opening and cleaning the carburetor 3 times. While opening the carburettor I noticed that pilot jets were very tight and I damaged screwdriver notch of other pilet jet and I would need specialtools to get it off. I left pilot jets there, because I thought that removing them is needed only for cleaning, but I'm not sure. Is it bad if pilot jets are very tight?
I also notised that my air filter bottom plate had detached, but all the problems started long before that. I had check air filter condition earlier. I glued it back to air filter, but there was no notable changes in functioning.
A friend of mine, who has experience, told me that he’s almost sure that it’s about the carburettors. He thought that mixture was too thin (this was before I realised that my fuel tap was stuck.) or o-rings or diaphragm are in bad shape. *So he told me to close and then open fuel mixture screws 1,5 rounds, but I realised that the screws were already 3 round open (and that is a lot) Maybe it has something to do with first owners tuning to the bike.
After I had realised that fueltap was maincause to stalling instead of thin mixture, I didnt make any changes to mixture. But the bike started to make lots of missfire and sparkplugs turned to black. I had check the spark plugs earlier and they were fine.
I closed the mixture screws and opened them 1,5 rounds. It didnt make much change. The bike still does lots of missfire at high RPMs and RPMs go up and down at idle RPMs. I think its possible that mixture is too too rich and it casues the problem. I haven't analysed bike much after fixing the screws, one reason to that *is I still don't have drivinglicense, so *I try not to drive, exept if I have to. I'm geting my driving license in about one month.
Juttelin tämän pyöristä kokeneen kaverin kanssa äskettäin ja hän oli sitä mieltä että bensantaso kaasarissa voisi olla pielessä. Hän kehoitti kääntelemään ja kokeilemaan seosruuveja. Näin alkuun puolisen kierrosta tai vähän alle kiinni.
Pieni heittelely samallaisissa, saman ikäluokan pyörissä on normaalia kuulema, mutta tässä pyörässä joutokäynnin heittely on todella rajua, enkä usko sen olevan normaalia. Missfire tosin voi olla normaalia, johtuen uudesta putkesta, mikäli vastapainetta ei tule tarpeeksi, tai sitten sytytyksen ajoitus saattaa olla pielessä.
Mahtaako vika löytyä seoksista ja korjautua seosruuveja säätämällä, tai onko muita ajatuksia? Jos oletetaan, että vika korjautuu seosruuveja kääntelemällä, onko vinkkejä, miten saan ne kohilleen? Huoltoon viemistä haluaisin välttää, sillä pyörä ei ole kalliitten huoltojen arvonen, kuhan se on sinnepäin, niin riittää minulle aivan hyvin.