help me identify these gs500 symptoms

[BockinBboy]

Did you lose the oring in the tops of the carbs (under the cap) when re assembling?

Correct me if I'm wrong, but if the o-rings are missing/wrong, the carbs would be getting more air, and likely increasing the RPMs, not killing the engine like OP said.

Just quickly read through this thread... In my mind, with solving one lean issue and still stuck with another lean issue... this quoted above throws out a red flag again... We certain they work as intended?

If you mess with mixture screws, set them to the general starting point at three turns out from lightly seated and don't stray far from it... I doubt the mixture screw is causing the issue and changing it much will move your target... no one likes chasing a moving target... I personally wouldn't mess with it other than ensuring its not on the extreme ends to start with... just until you get a noticeable change for the better elsewhere, then dial in on the mixture screw.

Also, I might have missed it but, did you check the carb boots for leaks? most common place, and super easy check with WD40... I know you mentioned you replaced them, but double check they are seated well if you haven't, and triple check with the WD40.

- Bboy

[piresito]

Try mixture screw 3 turns out from lightly seated. I mean, really light, like tinger tip in the bit of the screwdriver light. If not working, sync carbs. It can be done by measurement, or with the vaccum meter. No need for a very precise sync to begin with, just to be sure that there is not a big difference between them.

[Kijona]

You didn't mention the generation of the carbs but I'm assuming since you mentioned 37.5 that they are the older ones with less vacuum line bullshit.

Anyway, it's not imperative that the o-rings between the slide caps are of a specific diameter - just that they are of sufficient thickness to seal the area when the cap is tightened down. The ones that were in my perfectly functioning 97 carbs were really loose but did not affect it at all.

I would check to make sure you haven't accidentally snapped off one of the mixture needle tips. Tightening while dirty (not saying you did, but possible) can cause the tips to snap off.

Additionally, stock, my bike would not run AT ALL with 2.5 turns out on the mixture needles. I ended up with something like 3.5, so try 3 and see if that improves anything.

Finally, you may end up going to #40 pilot jets. I know it vastly improved things for me. Here's a video of my bike starting from dead cold with the #40 jets: http://www.youtube.com/watch?v=x5vidyo2_iw Keep in mind it was barely 50°F and the bike was stone cold. It started with no choke at all and then after about 15 seconds at 20% choke it ran perfectly with no choke at all. You'll notice it also didn't do that surging crap that you are likely to encounter without them.

[MongMan]

Thanks for all the great tips and advice guys! I have been putting things back together to get the conditions recommended in this thread, but haven't got a chance to start it yet. So far i have taken off the carbs and turned the mixtures 3 turns out from very tightly seated. Dohhh now i read from lightly seated >< ill still try it out though, got the airbox back on with the air filter (its always a tuff job for me lol), just need to hook up the tank and ill give it a test tomorrow and report back. Its a 91 bike that has tags from 2003 so i am assuming it has not been run for a very very long time. Im not exactly sure how long though (bought it like that) oh yea and the carbs are not synced i only eyeballed them to get them as close as possible when rebuilding them.

[Snake2715]

0A big tip with the carbs and air box.

Put the carbs on the airbox get those boots tight and mounted.

Then install the whole combo in the bike and the front boots. Makes things a lot easier. It will fit as a unit, just get it between the frame with a little finesse and go from there.

[Kijona]

Another small tip...you can use feeler gauges to bench sync the carbs.

[bombsquad83]

0A big tip with the carbs and air box.

Put the carbs on the airbox get those boots tight and mounted.

Then install the whole combo in the bike and the front boots. Makes things a lot easier. It will fit as a unit, just get it between the frame with a little finesse and go from there.

I actually find it easiest to take the air filter out and use my hand inside the airbox to make sure the carb to airbox boots are completely outside the carb mouth while you slide the airbox on.

[Snake2715]

?| I should have clarified that, yes without the filter in the air box.

[MongMan]

thanks for the tip much easier that way.

Ok i started it up today and here is what happened: on first startup i had the same problem i was having without the airbox and filter. the rpm was surging between 2-4k after warmed up and requiring choke to stay alive. So i sprayed WD40 all over the intake boots and nothing changed either. I expected this much though because i changed the boots and put new gaskets. So after reading about the mixture screws position relative to force, i turned them out 2 extra turns though it might have been 3 turns i forgot lol. So i am thinking i was around 6 turns out from bottoming them out originally. Started it up and the  surging was gone! it stayed at 2k rpm with choke on. So i turned in the idle screw until the rpm went way up high, then dropped the choke a little to get rpm back down, then turned the idle screw in some more to get rpms way high, then the choke down some more, continuing this routine until the bike ran at 1.5k rpm with choke completely off. I would love to say success story right about now but the last problem about the throttle response is not completely normal.

Now with the choke off and the bike idling ok, on initial twist of the throttle the rpm rises in a somewhat responsive way, except it takes a long time for the rpms to drop back down after letting go of the throttle. So this is where i am at currently, i didnt get to remove the spark plugs sorry it got too dark out when i finished, and also another thing i noticed is that i am not using the two gas vapor hoses connected to the bottom of the carbs. I plugged them in, but i didnt notice any difference, so i just left them off for now, because i am not using original tank yet. I think they are just for recycling the gas vapors from the tank, i just hope leaving the holes open in the carbs isint a problem is it? S