i am not sure if this is the place or not but if it is not could you please redirect me. i just bought a 02 gs500. it was laid down but i fixed her up in a couple days. the headlight housing was messed up. i just took the headlight out and put in 2 circle foglights. it works gread. the left case cover is scratched. and a couple on the back fairing. but it still looks really cool. its the silver and black model. it has a running problem though? the bike only has 8k on it but when it is at the low (idle) rpms it idles kinda ruff. and when it is cold or even sometimes warm it has a very slow throttle response. when i am riding it it rides fine and is kinda quick. it feels like it should be quicker though. the biggest problem is when i try and start out i almost have to drop the clutch at like 5k to get it to go(or just burn the crap out of it) if it give the bike a little pust it makes it allot easier. it also backfires when i start out, the backfire seems like it is coming out of the carb area of the enginge and not the exhaust? i did notice that there is 5 little wholes drilled in the back of the exhaust? they dont look stock? the air cleaner is kinda dirty but not to bad, i took it out for a 1 mile ride and it accelerated better from a stop but there was a loss in power. i have been working on bikes for awhile and i am stumped? the plugs have spark?  i checked the boots that connect the carbs to the head? also when i choke the bike i either have to choke it full or not at all, if i do it at half it just accelerates as high as it does when it is fully on? do you guys have any ideas? i also have a 91 that is being setup for race? i need wheel spacers and a clutch perch?? any ideas where i can get one? thank you guys for your help and safe Riding

the gs is underpowered at anything under 5k rpm but it shouldn't bog down and stall at 2k either. its a wet clutch so dont worry about burning it, ride the clutch when starting off you should be off the clutch at around 10mph. as for the rest of the problems and more troubleshooting hang on for some more people to reply 

yeah i have heard that they are underpowered, but it is deffinatly not right how it starts out. it almost boggs down and backfires a couple times, and i almost have to give it full throttle, then it will pick up after a couple second hesitation. thank you very much for replying

The 5 holes in the exhaust are not stock.  Also, Is there a possibility that the previous owner left the bike sitting for a while after crashing it?

Between these two things, it would be worth it to take the carbs off for cleaning and to see what size jets are in there.  Just cleaning them out may make everything run well enough, but with holes drilled in the exhaust, I'd want to know what else the PO monkeyed around with.  You may even want to richen the jets up a little (from stock settings).  Here's some info about rejetting: GS500 Wiki, What does one need to Rejet a 2001+ GS500

A 02 GS500 needs no rejetting unless the exhaust and/or intake have been modified.  My stock 02 runs perfectly smooth with over 50k miles on the clock.  Unlike my 97 GS which had to be revved to 4k and the clutch slipped to get it moving, the 02 takes off with modest reving and clutch slipping.  Just like a real bike does.   

Before you mess with the carbs or possibly mess them up further, check the valve clearances.  Whenever I had a GS that ran rough at startup and until warmed up, it had a tight valve.  Clearance increases as it warms up and it then smoothes out.

Also there could be a sparkplug wire loose in a coil, had this problem for a while.  Will show spark when tested but missfire under load when running.  GS500 spark plug wires should be tight in the coil like they were molded in, can't turn them either way on the screw post when new.

Always, check compression, check ignition, and then check carbs.  Simple finger in the hole and crank compression test will do, I don't boither with compression guage.  If finger pops out loud when cranked, it has enough compression to run good.

I'm curious as to what might be causing the engine to backfire through the carbs. I had that problem with my ATV when I let it sit for two months, I'd goose the throttle, it would bog cough air up through the airbox ... It went away when I drained the float bowl and restarted the bike. 

Quote from: gsJack on August 02, 2007, 05:53:54 AM
A 02 GS500 needs no rejetting unless the exhaust and/or intake have been modified.  My stock 02 runs perfectly smooth with over 50k miles on the clock.  Unlike my 97 GS which had to be revved to 4k and the clutch slipped to get it moving, the 02 takes off with modest reving and clutch slipping.  Just like a real bike does.   

Before you mess with the carbs or possibly mess them up further, check the valve clearances.  Whenever I had a GS that ran rough at startup and until warmed up, it had a tight valve.  Clearance increases as it warms up and it then smoothes out.

Also there could be a sparkplug wire loose in a coil, had this problem for a while.  Will show spark when tested but missfire under load when running.  GS500 spark plug wires should be tight in the coil like they were molded in, can't turn them either way on the screw post when new.

Always, check compression, check ignition, and then check carbs.  Simple finger in the hole and crank compression test will do, I don't boither with compression guage.  If finger pops out loud when cranked, it has enough compression to run good.

+1 on checking the valve clearance
I would also check the points on the timing rotor

I know there is a video floating around u tube on how to do the valve adjustment on the gs 
Im sure someone here has a link.

It's here: http://video.google.com/videoplay?docid=-2015554469142545363

Too bad we can't embed videos into the forum.

Cheers,
J

yep thats it...great video 

thanks groff

+1 on valve clearance.  Doing mine tomorrow.  Mine is starting up kinda slow at full choke.  Haven't adjusted them in about 8k mile.  It's about that time. 

Your backfire is probably the result of a rejet gone bad.  You could also have some air leaks around the carbs.  I'd pull the carbs, take them apart, check them out/clean them, check for leaks, and check the jetting.  While you've got them off, go ahead and check the valves.  good luck

ok so i ran it on pri and it seemed to help allot, there was maybe one backfire? it still feels like i am pulling a car when i try and take off? i only weigh 180? i did notice that when i put the choke on like half it bounces around allot eventually stalling? so its full choke or not? i also have a bike i was setting up for race that i bought from a guy, he modified the exhaust to fit some types of slip ons so i am gonna put that on, right know it has a stock ducati one that looks pretty good. it works good on the other bike? does anyone know how hard it would be to put the carbs from the 91 (race bike) onto it?

PRI keeps a constant stream of gas flowing into the carbs. Not ideal to run a bike like this, but you knew that - right? I think that if your carbs/jets are stock and you don't feel up for checking the valves... Then bring it to a mechanic, take the day off work, and watch him! Lots to learn. ALso, if you haven't, watch the valve video... It really is a great piece of work.

Your choke should only be on for the first minute before turning her off.. .Try to keep the choke around 2.5k RPM until she idles fine. I'm conscious the bike may have other problems preventing it from the ideal situation...

Regarding carbs/ducati exhaust... I think u should try to fix the problems you have first before creating other ones.

Cheers,
J