gs550 not running good

[mycat8urskidoo]

well i just got my carbs back on my bike this weekend, put stock main jets and mufflers ont he bike , put everything together, and the bike doesnt run to sweet, it seems like the carbs are sticking or something, when i shift, it only drops a couple rpms, unlike before were you could hear the drop in rpms, now it just sounds like its automatic or something, also i have absolutely no top end, with my straight pipes and the jets in it, i could hit 85-90, and now it wont go over 70 mph, i can hit 60 in 3rd gear, but 4-6 only gets me to 70, any ideas what it could be?, i've got everything set to stock, also, i think that it only runs on two cylinders when its idling (the left two pipes get hot), the right two are cold to the touch, but if i pull either of the right two plugs the bike shuts down, any help would be appreciated, i know its kind of a gaggle of a lot of things at once, but odnt know how else to explain it
thanks
Justin frank
oh yeah, i've put about 400 miles on it this week running this way (i'm laid off right now, and the weathers nice) this wont hurt the motor at all will it?

[Nessism]

Sounds like the bike is not running on all cylinders. It won't damage anything per say but it is putting a lot of stress on the pots that are firing.

[chef1366]

oh yeah, i've put about 400 miles on it this week running this way (i'm laid off right now, and the weathers nice) this wont hurt the motor at all will it?

If it's running lean it will. Check your spark plugs color and repost.
If someone modded your carbs for straight pipes maybe they also raised the needle jet. Check for stock notch setting on the needle or if there were washers added to raise the needle.
Also check for air leaks on the intake and airbox.

[mycat8urskidoo]

plugs

the plugs look about normal, nice and tan, i've had it running leaner before

[mycat8urskidoo]

compression test

well with it running like this i got a little nervous, and broke down and did a compression test, i warmed the bike up with a nice 10 mile ride, haha, pulled all the plugs , and did the cylinders one at a time with a WOT, results are from left to right when sitting on the bike
150/145/150/155
i dont know what acceptable numbers are, but those sound pretty good to me

[oldschoolorange]

those numbers are good at least balance wise, You probably screwed something up in the carb with the cold exhaust pipes, The reason teh bike dies is that it uses wasted spark ignition coil fires 2 plugs at the same time. check for vacume leaks around the intake boots with a spray bottle and water

[mycat8urskidoo]

those numbers are good at least balance wise,

they're not good compression wise?

[chef1366]

They are good. He meant that there isn't alot of difference between the compression of the different cylinders. You are not supposed to have more than fifteen psi difference.

[GS550joe]

also resync and retime

resync the carbs... it may take a couple of times through to get them ti settle in.. then retime the bike... just to get it set right.. you can retime with the static light just remember when the points close the light goes out and when they just break the light comes on...

It still sounds like a carb issue... mine had not run in several months ( years) and the carbs have been getting better the more I ride it.. Make sure you have the tubes hooked up to the airbox if original..

JP