I had purchased a 92 Gs500e 6 months ago, the bike had a Yoshi exhaust system and only had 5000 miles on it.

The bike was very loud, has power drop off at mid rpm, and stalls easily at idle. Previous owner did not know what component was intalled on the bike, as he was the second owner.

I recently purchased a stock pipe off ebay, and I had just finished installing on my bike. The bike now stalls when pull the throttle (drop in rpm), and can only idle with choke on.


I am stuck now, please help me, I just want a bike that runs perfect.....

Knee jerk reaction is to say that its too rich now. But if it only idles with the choke on, that indicates the idle circuit at least is way too lean.

You are going to have to take the carbs off and see what jetting is in it. Post on here what size main jets it has and if the needle is smooth and kinda fat or if it has any steps or necks to it (it will indicate if you have a DynoJet kit installed, I suspect you don't).
While you have them off and open you might as well clean them up too.

We can go from there...

I guess I should be more specific......

When I have the choke on, the engine's rpm is idle at 6000 after engine warms up. When I turn down the choke half way, rpm will to drop to 2000 for 3 seconds,  go up to 5000 for 3 seconds, then back down to 2000 for 3 seconds, and so on (does not idle). When I pull the throttle lightly, rpm drops dramatically and the engine will stall. Choke off will also stall the engine.


I really don't want to pull my bike apart at this time, please someone help me with solutions

Then you should take it to a shop, 'cause it needs pullin' apart...

Sounds like another case of the mysterious funky idle again.  The carbs need cleaning and rejetting back to stock configuration.

sorry

It sounds like one, or both, of your pilot jets are clogged at least.  I'd believe that if the bike has any accessory pipe, some rejetting has been performed.  

There are three main methods to rejet the carbs:  Dynojet kits, Factory Pro kits, and the patchwork method that you can find elsewhere in this forum.  If a Dynojet kit was used, the needle is a giveaway.  Also, Dynojet uses their own proprietary jets that aren't marked as to the size.  Factory Pro kits or the patchwork method uses stock Mikuni jets, that  have jet sizes marked.  

This past week, I pulled my carbs and performed some of the patchwork modifications; #40 pilot jets and slipping a #4 brass washer between the clip and spacer on the needle.  The difference was night and day, and the only imperfection at low speeds is a little weakness just off idle when the throttle is blipped.  I'm waiting until it gets a little warmer to tweak the idle screws to see if I can get that out.

I'm no mechanical wizard, but followed the Clymer manual and didn't really have problems.  In your case, it sounds like you might have some other issues to deal with.  It may be best to refer it to a good mechanic.  Welcome to the board and good luck with the sorting out process.  

QuoteThe difference was night and day, and the only imperfection at low speeds is a little weakness just off idle when the throttle is blipped.

If you go the patchword jetting method you can expect to live with some imperfection.  Most likely, the cause of your glitch is the washer under the stock needle because it isn't tapered to be repositioned like the adjustable type.  The hesitation can occasionally be annoying when getting on the throttle in mid-corner.

"patchwork"

took 3 hours taking off carb, main jet has 122.5 writing on it......

what does it mean?

Welcome to GStwin!

The 122.5 is the size of the main jet. That is also the stock size, so I suspect your carburetors are completely stock. Time to order some jets, purchase some #4 brass washers...

The pilot jets you need are size 40 non-bleed type pilot jets, one pair.
The main jets for a stock exhaust pipe are a size 125 large round Mikuni, one pair.
These can be ordered at your local motorcycle shop/dealer or m/c  accessory shop, like Cycle Gear, or online at mawonline, partsbandit.com, etc.
The washers can be obtained at a local hardware store. Probably Orchard Supply Hardware.

I could clean the main jet, pilot jet is clogged (hole is kind of small to clean, I might just buy new ones), I will replace all o-ring, 2 holes on each carb air intake has fuel/rust/water there, somehow I have to make sure they are all clean.

Any efficient way to clean all these including pilot jets?



PS. what's the washer for?

Sorry, I didn't reply sooner, I got busy at work.

To clean smaller holes, I clip a single wire off of a soft brass brisle brush and use that; sometimes gripping the wire with a pair of needle-nosed pliers.

To chemically clean, turn the cap over to the carb cleaner spray can and spray it full of carb cleaner and let the jets soak in that. Just make sure you don't spray any rubber parts.

The washers are used to raise the jet needle so it allows more gas to pass through the main jet tube. Put the washer underneath the clip on the needle. It helps with freeway and roll-on power.

I have a Problam like that when i warm up the engine, and i leave for alittle bit it stalls on me the RPM starts off at 1500 aboutish, but then goes down and then just dies, do i need to clean the carbs coz if i have to i'll wait till i go back to college and do it for free, isnit good to be a training bike mechnic , it's just annoying but i just leave the choke on for abit and it stops the engine from stalling.

Mine recently started to not hold idle without choke. :x
I am thinking it might be related to the cold weather but I  :dunno:
I went ahead and ordered bigger pilot jets. Although, I may wait for the wether to warm up before I try them.

mine did that when i first got it. was sitting for almost a year.(coaxed it to life with wd-40 ) , but it wouldnt idle, i went to auto parts place, got a gallon bucket of carb cleaner, with screen. i forgot to remove rubber rings inside the carb. they swelled up, i had to replace, but i put the parts, especially the needles and jets into the basket, into the can, and left it overnight. re-assembled the next day, it fired immediately, hadnt had prob since :mrgreen:

John,

You may just screw in the idle adjuster knob...

Mayz,

You may need to use the throttle after a couple of minutes of choke, to keep it from stalling. You really shouldn't have to leave the choke on for more than a minute and a half; and then just ride away!