I've recently gotten my '93 GS500E out of winter storage and she ran alright for a few days and started giving me some trouble. 

--Initial roll on Throttle bogs engine
--Sputtery and jumpy all througout the RPMs
--RPMs hang and come down slowly when I let off the throttle
--Sounds a little louder than normal.
--Overall she just feels sluggish and unresponsive

I've had this bike for 2 years now and the previous owner said the carbs had just been cleaned before I purchased it.
I read some threads and thought my carbs were gunked up, so I attempted to dissassemble.  Once I got the air filter box removed, I heard something strange and found the metal disc that should be glued to the end of the stock air filter was free and loose inside the box.

Basically my "filter" is allowing air to flow straight down the cylindrical foam filter and right into the carbs.

Do the symptoms described above sound like a lean mixture?
Is the old stock filter the reason for the sluggish performance?
Should I even bother cleaning the Carbs?

Thanks for the help.

Well allowing a whole load of air into the carbs is gunna make the bike run like crap unless you rejet.

so just replace the air filter. Then if you still have problems, clean the carbs.

If your bike has the stock air filter and exhaust keep it until you finger out the problem.Replace the air filter and spark plugs.If it still runs crapy,clean the carbs and rejet.40 and 127.5 should work for you but contact the great buddha on here for the correct jets.Make sure to let him know what elevation you ride at.I live at 900 feet above sea level and when I go to the mountains above me I swap carbs.It's 3500 to 5000 feet up there and my carbs for local riding lean out in the thin mountain air. 

Quote from: ben2go on April 17, 2008, 10:50:28 PM
If your bike has the stock air filter and exhaust keep it until you finger out the problem.Replace the air filter and spark plugs.If it still runs crapy,clean the carbs and rejet.40 and 127.5 should work for you but contact the great buddha on here for the correct jets.Make sure to let him know what elevation you ride at.I live at 900 feet above sea level and when I go to the mountains above me I swap carbs.It's 3500 to 5000 feet up there and my carbs for local riding lean out in the thin mountain air. 

When you GAIN altitude, your engine will run RICHER, not LEANER, due to the lack of oxygen in the air:

LESS OXYGEN = MORE GAS = RICH CONDITION

MORE OXYGEN = LESS GAS = LEAN CONDITION

IOW, the INCREASE in altitude causes a DECREASE in the available oxygen in the air. The decrease in oxygen means that you now have MORE gas in the fuel-to-air ratio, which is RICHNESS. If you lived near Denver, and rode down to the Gulf coast, you'd have changed the ratio in the opposite direction. You would have more OXYGEN in the air, which would cause a LEAN condition.

For those that don't know, LEANNESS is BAD. The engine will run HOTTER, which can burn the exhaust valves, or in an extreme case, melt the tops of the pistons. MELTED PISTONS = MAJOR BAD KARMA.

ALWAYS better to be too rich, which can lead to fouled sparkplugs, than too lean, which can lead to expensive engine repairs, or swapping engines.

As a general rule, CV carbs (also known generically as "constant vacuum" and "constant velocity" carbs), which have been in widespread use on most streetbikes sold in the US since the mid-1980's, don't have much problem with altitude changes. When I lived at sealevel (OK, so the mean altitude was actually 35 feet above sealevel), I spent a lot of time in an area the locals call "the Playground", where the main road crossed 7000 feet. The engine would run rich, but was certainly rideable, and dropping back down below 5000 feet, things would start to clear up. By the time I got back to sealevel, the engine would run normally.

Most older (pre-80's) motorcycles sold in the US market used NON-CV carbs, and they had much more obvious problems with major changes in altitude. I had a friend who ran his old Bultaco Matador into the canyons with me, and he'd actually change his jets in a rest area once he got above 3000 feet, because his old 'Taco engine was a blubbering mess up there. He'd have to change them again on the way home, or risk running the engine too lean at the lower elevations.

The rubber diaphragms used in CV carbs tends to negate the effects of altitude changes (depending on how drastic the change actually is); non-CV carbs don't use diaphragms, so they are much more sensitive to changes. A LOT has been posted about this subject; you can Google it to learn more.

Hope this helps to clarify the difference between RICH and LEAN.

Good read GSnoober... tnks.

Quote from: groff22 on April 18, 2008, 01:02:27 PM
Good read GSnoober... tnks.

Hope that did help you, and others who aren't yet experts in carburetion... Much as I like fuel injection in four-wheeled vehicles, I sorta cut my teeth on carbureted motorcycle engines. Someday, fairly soon I'd bet, the US will probably force all new motorcycles sold here to switch to some type of fuel injection, and kill off carburetors on motorcycles. Once that happens, rejetting motorcycle carbs will probably be a lost art (in the US market), and only cranky old bastids will remember the details... all of which should help to keep Srinath / The Buddha gainfully employed for a LONG time to come