poor idle

[apollonrop]

Hey Paul,

Good news, I think I may have found at least one problem in our pursuit for a solution for our idle issues.  On my carbs it turns out that I accidentally jammed the spring in one of the idle mixture screw housings which was allowing air to bypass the seal on that particular carb.  As I mentioned before, I am doing a full over-haul on all 4 of my carbs and as a result I decided to remove all the non metallic pieces in order to soak them.  Now the frustrating part for me is that I found another issue with my set up.  That is to say that the guy who owned the bike before me installed one of the other three carbs with a missing washer in the idle mix screw and of the two remaining he didn't even install a seal in the number one carb.  This actually resulted in about a 30% decrease in efficiency in that particular cylinder...as I found out when I did my compression test as well as rough starts and poor idle, in the past. 

So how does this affect you? 

Well, since your bike is having the choking and low power over the low rpm range too I believe that you are probably having the same issue...that is an air leak in this or a similar circuit (i.e. the needle jet, jet needle or jet block seals, your slide maybe sticking too or you could have a clogged pilot jet).  I had all these things and more and some how it has taken me a while to find each one.  Obviously since my bike is running properly over the higher rpms my work so far has had some success.  So if I were you I would, as I mentioned to you before, replace all the seals in all your carbs and I would also soak them in a carb cleaner solution.  Truth be told, given your climate it is probable that most of the seals on your carbs are hardened, brittle and not sealing so new seals will go along way.     

        The how to on carb soaking, start with disassembling all the plastic and rubber parts.  Remember what goes where and work on a clean bench space.  Cuz parts tend to go everywhere when you do this kinda thing.  As for the brass parts, some are designed to be removable and others aren't.  The removable ones I know about include: the pilot jet, the main jet, the floats themselves (although that may depend on the model of the carb) the Jet block its self and the needle jets as well as the jet needles.  The idle mix screws are sometimes permanent other times, like on my bike and probably yours, they aren't.  On the top cover (where the diaphragm is located) there is a seal and a spring too those need to be removed...you don't want to soak them.  Also while you have them disassembled you going to want to check them for cracks, tears and poor seal-ability.  A faulty diaphragm is an opportunity for many headaches down the road.  Finally I have been using speaker wire to clean out the rest of the really small brass pipes in the carbs you can use anything that fits.  As for clean up I'd suggest you use Vaseline to re seal the new seal thereby adding to their lifespan.  I always rub them with some sort of coating before installing... this also helps you later on down the road when your looking for other problems within the carbs and you have to re-disassemble them to find them.  The Vaseline will help them stay sealed moist and affective.  Good luck and keep me posted.

[Dink_1170]

I bought my wife a GSX250 some years ago and had a mechanic I trusted fully service it. It ended up coming back with a poor idle issue. It had stumped the mechanic and everybody else he had consulted to attempt to fix it; he ended up giving it back with apologies that the idle was the best he could do. I replaced the regulator rectifier and solved the issue at one stroke;the one thing they hadn't tried to fix it.

Dink

[dbcanh]

I took my bike back to shop on the 28-12-2009, i have only just got it back today, nearly a month later,  tappets adjusted has 1 and 4 intake cylinders were out? but with in spec mechanic said. also he tried adjusting the mixture screws with there special tool  ( long probe with a slotted blade and a dial on the other end) but engine still hunting really bad. Also the sync screw was bent, (i am not supprized has the carbs have been balanced 7 times!! now. i had to give them my spare set of carbs to take the screw off!, has there was a argument on who had bent it. He reckons he checked every known cause of this problem. They ended up buying some more carbs second hand and putting them on, and setting bike up with them, all i can say it is running for now, we shall see how it goes, i don`t think they really knew what the problem was, I  think they were glad to see the back of me!! That`s the trouble with second hand bikes, you don`t know the history or who has messed with it before, i think your buying someone else`s problems, this bandit 14000 on clock was part ex for a new bandit, before i bought it.